diff --git a/src/anthropic/lib/bedrock/_auth.py b/src/anthropic/lib/bedrock/_auth.py
index 95c820f6..dcada500 100644
--- a/src/anthropic/lib/bedrock/_auth.py
+++ b/src/anthropic/lib/bedrock/_auth.py
@@ -64,3 +64,16 @@ def get_auth_headers(
     prepped = request.prepare()
 
     return {key: value for key, value in dict(prepped.headers).items() if value is not None}
+
+def get_credentials(
+    *,
+    aws_role_arn: str | None,
+) -> dict:
+    import boto3
+
+    response = boto3.client('sts').assume_role(RoleArn=aws_role_arn, RoleSessionName='assume-role')
+    return {
+        'aws_access_key': response['Credentials']['AccessKeyId'],
+        'aws_secret_key': response['Credentials']['SecretAccessKey'],
+        'aws_session_token': response['Credentials']['SessionToken'],
+    }
\ No newline at end of file
diff --git a/src/anthropic/lib/bedrock/_client.py b/src/anthropic/lib/bedrock/_client.py
index f7298adc..6de7e7ed 100644
--- a/src/anthropic/lib/bedrock/_client.py
+++ b/src/anthropic/lib/bedrock/_client.py
@@ -95,6 +95,7 @@ def __init__(
         aws_access_key: str | None = None,
         aws_region: str | None = None,
         aws_session_token: str | None = None,
+        aws_role_arn: str | None = None,
         base_url: str | httpx.URL | None = None,
         timeout: float | httpx.Timeout | None | NotGiven = NOT_GIVEN,
         max_retries: int = DEFAULT_MAX_RETRIES,
@@ -122,6 +123,13 @@ def __init__(
 
         self.aws_session_token = aws_session_token
 
+        if aws_role_arn is not None:
+            from ._auth import get_credentials
+            cred = get_credentials(aws_role_arn=aws_role_arn)
+            self.aws_access_key = cred["aws_access_key"]
+            self.aws_secret_key = cred["aws_secret_key"]
+            self.aws_session_token = cred["aws_session_token"]
+
         if base_url is None:
             base_url = os.environ.get("ANTHROPIC_BEDROCK_BASE_URL")
         if base_url is None: