Closed ruptures of the flexor tendon have been described in association with distinct underlying pathologies. The spontaneous rupture of the flexor tendon secondary to axial tendon loading alone is infrequent. The previously reported cases with spontaneous rupture were mostly men aged 30 to 60 years. In addition, rupture occurred during manual labor with the fingers engaged in forceful or resisted flexion. Labor-associated forceful usage, in addition to gender and age, has been implicated in the pathogenesis of the stressful rupture of the flexor tendon. Here we report a case with spontaneous rupture of the flexor digitorum profundus (FDP) and superficialis of the index finger as well as the flexor pollicis longus (FPL). Unlike the previously reported cases the present patient was an elderly woman engaged in no apparent occupational activities. In the present case, however, the patient had a particular predisposing condition. The patient used only the right hand during her whole lifetime because of a perinatal brachial plexus injury on the contralateral arm. The present case may show that the tendons of an elderly patient could yield to the axial loading of normal levels of activities of daily living when the usage is as incessant as in the present patient.