Focal myositis is an uncommon benign inflammatory myopathy of unknown cause affecting skeletal muscle, and presenting as a localized painful swelling within the soft tissue of an extremity. According to some reports, focal myositis may occur in patients with rheumatoid arthritis, sarcoidosis, and other connective tissue diseases. To our knowledge, there has been no case report of focal myositis associated with rheumatoid arthritis. We report first case of focal myositis in a patient with rheumatoid arthritis.