diff --git a/src/crewai/agents/cache/cache_handler.py b/src/crewai/agents/cache/cache_handler.py
index 09dd76f268..0cf2e259bd 100644
--- a/src/crewai/agents/cache/cache_handler.py
+++ b/src/crewai/agents/cache/cache_handler.py
@@ -1,15 +1,28 @@
 from typing import Any, Dict, Optional
+import threading
+from threading import local
 
 from pydantic import BaseModel, PrivateAttr
 
 
+_thread_local = local()
+
+
 class CacheHandler(BaseModel):
     """Callback handler for tool usage."""
 
     _cache: Dict[str, Any] = PrivateAttr(default_factory=dict)
 
+    def _get_lock(self):
+        """Get a thread-local lock to avoid pickling issues."""
+        if not hasattr(_thread_local, "cache_lock"):
+            _thread_local.cache_lock = threading.Lock()
+        return _thread_local.cache_lock
+
     def add(self, tool, input, output):
-        self._cache[f"{tool}-{input}"] = output
+        with self._get_lock():
+            self._cache[f"{tool}-{input}"] = output
 
     def read(self, tool, input) -> Optional[str]:
-        return self._cache.get(f"{tool}-{input}")
+        with self._get_lock():
+            return self._cache.get(f"{tool}-{input}")
diff --git a/src/crewai/crew.py b/src/crewai/crew.py
index d488783eae..35e6ad4f28 100644
--- a/src/crewai/crew.py
+++ b/src/crewai/crew.py
@@ -88,7 +88,7 @@ class Crew(BaseModel):
     _rpm_controller: RPMController = PrivateAttr()
     _logger: Logger = PrivateAttr()
     _file_handler: FileHandler = PrivateAttr()
-    _cache_handler: InstanceOf[CacheHandler] = PrivateAttr(default=CacheHandler())
+    _cache_handler: InstanceOf[CacheHandler] = PrivateAttr()
     _short_term_memory: Optional[InstanceOf[ShortTermMemory]] = PrivateAttr()
     _long_term_memory: Optional[InstanceOf[LongTermMemory]] = PrivateAttr()
     _entity_memory: Optional[InstanceOf[EntityMemory]] = PrivateAttr()
diff --git a/src/crewai/telemetry/telemetry.py b/src/crewai/telemetry/telemetry.py
index 984a4938de..c4d15165fd 100644
--- a/src/crewai/telemetry/telemetry.py
+++ b/src/crewai/telemetry/telemetry.py
@@ -4,11 +4,15 @@
 import json
 import os
 import platform
+import threading
 import warnings
 from contextlib import contextmanager
 from importlib.metadata import version
+from threading import local
 from typing import TYPE_CHECKING, Any, Optional
 
+_thread_local = local()
+
 
 @contextmanager
 def suppress_warnings():
@@ -76,12 +80,20 @@ def __init__(self):
                 raise  # Re-raise the exception to not interfere with system signals
             self.ready = False
 
+    def _get_lock(self):
+        """Get a thread-local lock to avoid pickling issues."""
+        if not hasattr(_thread_local, "telemetry_lock"):
+            _thread_local.telemetry_lock = threading.Lock()
+        return _thread_local.telemetry_lock
+
     def set_tracer(self):
         if self.ready and not self.trace_set:
             try:
-                with suppress_warnings():
-                    trace.set_tracer_provider(self.provider)
-                    self.trace_set = True
+                with self._get_lock():
+                    if not self.trace_set:  # Double-check to avoid race condition
+                        with suppress_warnings():
+                            trace.set_tracer_provider(self.provider)
+                            self.trace_set = True
             except Exception:
                 self.ready = False
                 self.trace_set = False
@@ -90,7 +102,8 @@ def _safe_telemetry_operation(self, operation):
         if not self.ready:
             return
         try:
-            operation()
+            with self._get_lock():
+                operation()
         except Exception:
             pass
 
diff --git a/tests/concurrency_test.py b/tests/concurrency_test.py
new file mode 100644
index 0000000000..797af3ea7d
--- /dev/null
+++ b/tests/concurrency_test.py
@@ -0,0 +1,186 @@
+import asyncio
+import time
+from concurrent.futures import ThreadPoolExecutor, as_completed
+import pytest
+from unittest.mock import patch
+
+from crewai import Agent, Crew, Task
+
+
+class MockLLM:
+    """Mock LLM for testing."""
+    def __init__(self, model="gpt-3.5-turbo", **kwargs):
+        self.model = model
+        self.stop = None
+        self.timeout = None
+        self.temperature = None
+        self.top_p = None
+        self.n = None
+        self.max_completion_tokens = None
+        self.max_tokens = None
+        self.presence_penalty = None
+        self.frequency_penalty = None
+        self.logit_bias = None
+        self.response_format = None
+        self.seed = None
+        self.logprobs = None
+        self.top_logprobs = None
+        self.base_url = None
+        self.api_version = None
+        self.api_key = None
+        self.callbacks = []
+        self.context_window_size = 8192
+        self.kwargs = {}
+        
+        for key, value in kwargs.items():
+            setattr(self, key, value)
+
+    def complete(self, prompt, **kwargs):
+        """Mock completion method."""
+        return f"Mock response for: {prompt[:20]}..."
+
+    def chat_completion(self, messages, **kwargs):
+        """Mock chat completion method."""
+        return {"choices": [{"message": {"content": "Mock response"}}]}
+
+    def function_call(self, messages, functions, **kwargs):
+        """Mock function call method."""
+        return {
+            "choices": [
+                {
+                    "message": {
+                        "content": "Mock response",
+                        "function_call": {
+                            "name": "test_function",
+                            "arguments": '{"arg1": "value1"}'
+                        }
+                    }
+                }
+            ]
+        }
+        
+    def supports_stop_words(self):
+        """Mock supports_stop_words method."""
+        return False
+        
+    def supports_function_calling(self):
+        """Mock supports_function_calling method."""
+        return True
+        
+    def get_context_window_size(self):
+        """Mock get_context_window_size method."""
+        return self.context_window_size
+        
+    def call(self, messages, callbacks=None):
+        """Mock call method."""
+        return "Mock response from call method"
+        
+    def set_callbacks(self, callbacks):
+        """Mock set_callbacks method."""
+        self.callbacks = callbacks
+        
+    def set_env_callbacks(self):
+        """Mock set_env_callbacks method."""
+        pass
+
+
+def create_test_crew():
+    """Create a simple test crew for concurrency testing."""
+    with patch("crewai.agent.LLM", MockLLM):
+        agent = Agent(
+            role="Test Agent",
+            goal="Test concurrent execution",
+            backstory="I am a test agent for concurrent execution",
+        )
+
+        task = Task(
+            description="Test task for concurrent execution",
+            expected_output="Test output",
+            agent=agent,
+        )
+
+        crew = Crew(
+            agents=[agent],
+            tasks=[task],
+            verbose=False,
+        )
+
+        return crew
+
+
+def test_threading_concurrency():
+    """Test concurrent execution using ThreadPoolExecutor."""
+    num_threads = 5
+    results = []
+
+    def generate_response(idx):
+        try:
+            crew = create_test_crew()
+            with patch("crewai.agent.LLM", MockLLM):
+                output = crew.kickoff(inputs={"test_input": f"input_{idx}"})
+            return output
+        except Exception as e:
+            pytest.fail(f"Exception in thread {idx}: {e}")
+            return None
+
+    with ThreadPoolExecutor(max_workers=num_threads) as executor:
+        futures = [executor.submit(generate_response, i) for i in range(num_threads)]
+
+        for future in as_completed(futures):
+            result = future.result()
+            assert result is not None
+            results.append(result)
+
+    assert len(results) == num_threads
+
+
+@pytest.mark.asyncio
+async def test_asyncio_concurrency():
+    """Test concurrent execution using asyncio."""
+    num_tasks = 5
+    sem = asyncio.Semaphore(num_tasks)
+
+    async def generate_response_async(idx):
+        async with sem:
+            try:
+                crew = create_test_crew()
+                with patch("crewai.agent.LLM", MockLLM):
+                    output = await crew.kickoff_async(inputs={"test_input": f"input_{idx}"})
+                return output
+            except Exception as e:
+                pytest.fail(f"Exception in task {idx}: {e}")
+                return None
+
+    tasks = [generate_response_async(i) for i in range(num_tasks)]
+    results = await asyncio.gather(*tasks)
+
+    assert len(results) == num_tasks
+    assert all(result is not None for result in results)
+
+
+@pytest.mark.asyncio
+async def test_extended_asyncio_concurrency():
+    """Extended test for asyncio concurrency with more iterations."""
+    num_tasks = 5  # Reduced from 10 for faster testing
+    iterations = 2  # Reduced from 3 for faster testing
+    sem = asyncio.Semaphore(num_tasks)
+
+    async def generate_response_async(idx):
+        async with sem:
+            crew = create_test_crew()
+            for i in range(iterations):
+                try:
+                    with patch("crewai.agent.LLM", MockLLM):
+                        output = await crew.kickoff_async(
+                            inputs={"test_input": f"input_{idx}_{i}"}
+                        )
+                    assert output is not None
+                except Exception as e:
+                    pytest.fail(f"Exception in task {idx}, iteration {i}: {e}")
+                    return False
+            return True
+
+    tasks = [generate_response_async(i) for i in range(num_tasks)]
+    results = await asyncio.gather(*tasks)
+
+    assert all(results)