A boy developed sudden severe generalized muscle stiffness, bulbar weakness and passed dark coloured urine. Laboratory tests revealed marked elevation of creatinine kinase(CK) levels and myoglobinuria. Histopathology of quadriceps muscle showed features of acute rhabdomyolysis. Patient made complete clinical recovery over a period of three weeks and CK returned to normal level. The possible aetiologies of non-traumatic rhabdomyolysis are discussed and the relevant literature reviewed.