diff --git a/packages/opentelemetry-instrumentation-voyageai/opentelemetry/instrumentation/voyageai/__init__.py b/packages/opentelemetry-instrumentation-voyageai/opentelemetry/instrumentation/voyageai/__init__.py
index dcf85b9a19..129e9329b8 100644
--- a/packages/opentelemetry-instrumentation-voyageai/opentelemetry/instrumentation/voyageai/__init__.py
+++ b/packages/opentelemetry-instrumentation-voyageai/opentelemetry/instrumentation/voyageai/__init__.py
@@ -13,7 +13,7 @@
     set_span_request_attributes,
     set_span_response_attributes,
 )
-from opentelemetry.instrumentation.voyageai.utils import dont_throw
+from opentelemetry.instrumentation.voyageai.utils import dont_throw, get_call_arguments
 from opentelemetry.instrumentation.voyageai.version import __version__
 from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
 from opentelemetry.instrumentation.utils import (
@@ -117,8 +117,9 @@ def _wrap(
     )
 
     try:
-        set_span_request_attributes(span, kwargs)
-        _handle_input_content(span, operation_name, kwargs)
+        call_args = get_call_arguments(wrapped, args, kwargs)
+        set_span_request_attributes(span, call_args)
+        _handle_input_content(span, operation_name, call_args)
 
         response = wrapped(*args, **kwargs)
 
@@ -161,8 +162,9 @@ async def _awrap(
     )
 
     try:
-        set_span_request_attributes(span, kwargs)
-        _handle_input_content(span, operation_name, kwargs)
+        call_args = get_call_arguments(wrapped, args, kwargs)
+        set_span_request_attributes(span, call_args)
+        _handle_input_content(span, operation_name, call_args)
 
         response = await wrapped(*args, **kwargs)
 
diff --git a/packages/opentelemetry-instrumentation-voyageai/opentelemetry/instrumentation/voyageai/utils.py b/packages/opentelemetry-instrumentation-voyageai/opentelemetry/instrumentation/voyageai/utils.py
index f4ff8183c3..c616e02312 100644
--- a/packages/opentelemetry-instrumentation-voyageai/opentelemetry/instrumentation/voyageai/utils.py
+++ b/packages/opentelemetry-instrumentation-voyageai/opentelemetry/instrumentation/voyageai/utils.py
@@ -1,4 +1,5 @@
 import dataclasses
+import inspect
 import json
 import logging
 import os
@@ -75,3 +76,19 @@ def to_dict(obj):
         return dict(obj)
     except Exception:
         return obj
+
+
+def get_call_arguments(wrapped, args, kwargs):
+    """
+    Returns the arguments of a wrapped call as a single name -> value dict.
+
+    Voyage AI methods such as ``embed(texts, model=...)`` and
+    ``rerank(query, documents, model)`` are commonly called with positional
+    arguments, so reading ``kwargs`` alone would silently drop them.
+    Falls back to ``kwargs`` if the signature cannot be bound.
+    """
+    try:
+        bound = inspect.signature(wrapped).bind_partial(*args, **kwargs)
+        return dict(bound.arguments)
+    except Exception:
+        return dict(kwargs)
diff --git a/packages/opentelemetry-instrumentation-voyageai/tests/test_positional_args.py b/packages/opentelemetry-instrumentation-voyageai/tests/test_positional_args.py
new file mode 100644
index 0000000000..a3dc5c7cb5
--- /dev/null
+++ b/packages/opentelemetry-instrumentation-voyageai/tests/test_positional_args.py
@@ -0,0 +1,60 @@
+"""Regression tests: span attributes must be captured for positional arguments.
+
+The Voyage AI docs call ``embed(texts, model=...)`` and
+``rerank(query, documents, model)`` positionally, so the instrumentation must
+not rely on ``kwargs`` alone. These tests stub the network layer, so they need
+neither an API key nor a VCR cassette.
+"""
+
+import json
+from types import SimpleNamespace
+
+import pytest
+import voyageai
+from opentelemetry.instrumentation.voyageai import VoyageAIInstrumentor
+from opentelemetry.semconv._incubating.attributes import (
+    gen_ai_attributes as GenAIAttributes,
+)
+
+TEXTS = ["Paris is in France.", "Berlin is in Germany."]
+QUERY = "What is the capital of France?"
+DOCUMENTS = ["Paris", "Berlin", "Madrid"]
+
+
+@pytest.fixture
+def stubbed_instrumented_client(tracer_provider, monkeypatch):
+    def fake_embed(self, texts, model=None, input_type=None, **kwargs):
+        return SimpleNamespace(total_tokens=7, embeddings=[[0.1, 0.2]] * len(texts))
+
+    def fake_rerank(self, query, documents, model, top_k=None, **kwargs):
+        return SimpleNamespace(total_tokens=7, results=[])
+
+    monkeypatch.setattr(voyageai.Client, "embed", fake_embed)
+    monkeypatch.setattr(voyageai.Client, "rerank", fake_rerank)
+
+    instrumentor = VoyageAIInstrumentor()
+    instrumentor.instrument(tracer_provider=tracer_provider)
+    yield voyageai.Client(api_key="test_api_key")
+    instrumentor.uninstrument()
+
+
+def test_embed_positional_args(span_exporter, stubbed_instrumented_client):
+    stubbed_instrumented_client.embed(TEXTS, "voyage-3-lite", input_type="document")
+
+    (span,) = span_exporter.get_finished_spans()
+    assert span.attributes[GenAIAttributes.GEN_AI_REQUEST_MODEL] == "voyage-3-lite"
+    assert span.attributes[f"{GenAIAttributes.GEN_AI_PROMPT}.0.role"] == "user"
+    content = json.loads(span.attributes[f"{GenAIAttributes.GEN_AI_PROMPT}.0.content"])
+    assert [item["text"] for item in content] == TEXTS
+
+
+def test_rerank_positional_args(span_exporter, stubbed_instrumented_client):
+    stubbed_instrumented_client.rerank(QUERY, DOCUMENTS, "rerank-2-lite", top_k=2)
+
+    (span,) = span_exporter.get_finished_spans()
+    prefix = GenAIAttributes.GEN_AI_PROMPT
+    assert span.attributes[GenAIAttributes.GEN_AI_REQUEST_MODEL] == "rerank-2-lite"
+    for index, document in enumerate(DOCUMENTS):
+        assert span.attributes[f"{prefix}.{index}.content"] == document
+    assert span.attributes[f"{prefix}.{len(DOCUMENTS)}.role"] == "user"
+    assert span.attributes[f"{prefix}.{len(DOCUMENTS)}.content"] == QUERY