Abstract We describe a patient who presented with flexion contractures of the bilateral fingers due to tenosynovitis of the flexor digitorum tendons as an initial manifestation of systemic lupus erythematosus (SLE). A 17-year-old woman had abrupt onset of diffuse swelling and flexion contractures in the bilateral fingers, accompanied by polyarthritis and cervical lymphadenopathy. Magnetic resonance imaging (MRI) showed flexor tenosynovitis of the hands. A diagnosis of SLE was made by immunological and hematological tests, and treatment with oral corticosteroids resulted in a rapid and complete disappearance of the flexion contractures.