A woman with systemic lupus erythematosus developed severe myopathy after a septicemic episode, and her treatment before admission was hydroxychloroquine sulfate and prednisolone. A muscle biopsy revealed no evidence of vasculitis and creatine kinase was normal. She continued taking maintenance prednisolone and with intensive physiotherapy her muscle strength slowly returned. It is possible that the hydroxychloroquine was responsible for the myopathy.