diff --git a/agentops/instrumentation/agentic/google_adk/patch.py b/agentops/instrumentation/agentic/google_adk/patch.py
index 172c41ab7..0fd652f68 100644
--- a/agentops/instrumentation/agentic/google_adk/patch.py
+++ b/agentops/instrumentation/agentic/google_adk/patch.py
@@ -267,12 +267,20 @@ def _extract_llm_attributes(llm_request_dict: dict, llm_response: Any) -> dict:
             # Usage metadata
             if "usage_metadata" in response_dict:
                 usage = response_dict["usage_metadata"]
+                # Support both old-style (prompt_token_count/candidates_token_count) and
+                # new ADK 2.1+ style (input_tokens/output_tokens) field names (#1418).
                 if "prompt_token_count" in usage:
                     attributes[SpanAttributes.LLM_USAGE_PROMPT_TOKENS] = usage["prompt_token_count"]
+                elif "input_tokens" in usage:
+                    attributes[SpanAttributes.LLM_USAGE_PROMPT_TOKENS] = usage["input_tokens"]
                 if "candidates_token_count" in usage:
                     attributes[SpanAttributes.LLM_USAGE_COMPLETION_TOKENS] = usage["candidates_token_count"]
+                elif "output_tokens" in usage:
+                    attributes[SpanAttributes.LLM_USAGE_COMPLETION_TOKENS] = usage["output_tokens"]
                 if "total_token_count" in usage:
                     attributes[SpanAttributes.LLM_USAGE_TOTAL_TOKENS] = usage["total_token_count"]
+                elif "total_tokens" in usage:
+                    attributes[SpanAttributes.LLM_USAGE_TOTAL_TOKENS] = usage["total_tokens"]
 
                 # Additional token details if available
                 if "prompt_tokens_details" in usage:
diff --git a/tests/unit/instrumentation/google_adk/__init__.py b/tests/unit/instrumentation/google_adk/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/unit/instrumentation/google_adk/test_token_extraction.py b/tests/unit/instrumentation/google_adk/test_token_extraction.py
new file mode 100644
index 000000000..762a40b9a
--- /dev/null
+++ b/tests/unit/instrumentation/google_adk/test_token_extraction.py
@@ -0,0 +1,109 @@
+"""Tests for Google ADK token usage attribute extraction (issue #1418).
+
+Verifies that both old-style (prompt_token_count / candidates_token_count)
+and new ADK 2.1+ style (input_tokens / output_tokens) field names are
+correctly mapped to the SpanAttributes constants.
+"""
+
+import json
+import pytest
+from unittest.mock import MagicMock, patch
+
+from agentops.semconv import SpanAttributes
+
+
+def _extract_usage_attributes(usage_metadata: dict) -> dict:
+    """Replicate the attribute extraction logic from patch.py for isolated testing."""
+    attributes = {}
+    usage = usage_metadata
+
+    if "prompt_token_count" in usage:
+        attributes[SpanAttributes.LLM_USAGE_PROMPT_TOKENS] = usage["prompt_token_count"]
+    elif "input_tokens" in usage:
+        attributes[SpanAttributes.LLM_USAGE_PROMPT_TOKENS] = usage["input_tokens"]
+
+    if "candidates_token_count" in usage:
+        attributes[SpanAttributes.LLM_USAGE_COMPLETION_TOKENS] = usage["candidates_token_count"]
+    elif "output_tokens" in usage:
+        attributes[SpanAttributes.LLM_USAGE_COMPLETION_TOKENS] = usage["output_tokens"]
+
+    if "total_token_count" in usage:
+        attributes[SpanAttributes.LLM_USAGE_TOTAL_TOKENS] = usage["total_token_count"]
+    elif "total_tokens" in usage:
+        attributes[SpanAttributes.LLM_USAGE_TOTAL_TOKENS] = usage["total_tokens"]
+
+    return attributes
+
+
+class TestOldStyleTokenFields:
+    """Old-style field names used by Google ADK < 2.1."""
+
+    def test_prompt_token_count_mapped(self):
+        usage = {"prompt_token_count": 50, "candidates_token_count": 100, "total_token_count": 150}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_PROMPT_TOKENS] == 50
+
+    def test_candidates_token_count_mapped(self):
+        usage = {"prompt_token_count": 50, "candidates_token_count": 100, "total_token_count": 150}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_COMPLETION_TOKENS] == 100
+
+    def test_total_token_count_mapped(self):
+        usage = {"prompt_token_count": 50, "candidates_token_count": 100, "total_token_count": 150}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_TOTAL_TOKENS] == 150
+
+
+class TestNewStyleTokenFields:
+    """New-style field names introduced in Google ADK 2.1+ (issue #1418)."""
+
+    def test_input_tokens_mapped(self):
+        usage = {"input_tokens": 30, "output_tokens": 70, "total_tokens": 100}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_PROMPT_TOKENS] == 30
+
+    def test_output_tokens_mapped(self):
+        usage = {"input_tokens": 30, "output_tokens": 70, "total_tokens": 100}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_COMPLETION_TOKENS] == 70
+
+    def test_total_tokens_mapped(self):
+        usage = {"input_tokens": 30, "output_tokens": 70, "total_tokens": 100}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_TOTAL_TOKENS] == 100
+
+
+class TestTokenFieldPriority:
+    """Old-style fields take priority over new-style when both are present."""
+
+    def test_old_style_prompt_takes_priority(self):
+        usage = {"prompt_token_count": 50, "input_tokens": 30}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_PROMPT_TOKENS] == 50
+
+    def test_old_style_completion_takes_priority(self):
+        usage = {"candidates_token_count": 100, "output_tokens": 70}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_COMPLETION_TOKENS] == 100
+
+    def test_old_style_total_takes_priority(self):
+        usage = {"total_token_count": 150, "total_tokens": 100}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_TOTAL_TOKENS] == 150
+
+
+class TestMissingFields:
+    """Attributes absent when the usage dict does not contain token fields."""
+
+    def test_empty_usage_has_no_token_attrs(self):
+        attrs = _extract_usage_attributes({})
+        assert SpanAttributes.LLM_USAGE_PROMPT_TOKENS not in attrs
+        assert SpanAttributes.LLM_USAGE_COMPLETION_TOKENS not in attrs
+        assert SpanAttributes.LLM_USAGE_TOTAL_TOKENS not in attrs
+
+    def test_partial_usage_maps_available_fields_only(self):
+        usage = {"input_tokens": 10}
+        attrs = _extract_usage_attributes(usage)
+        assert attrs[SpanAttributes.LLM_USAGE_PROMPT_TOKENS] == 10
+        assert SpanAttributes.LLM_USAGE_COMPLETION_TOKENS not in attrs
+        assert SpanAttributes.LLM_USAGE_TOTAL_TOKENS not in attrs