Dapsone syndrome or sulphone syndrome was noticed within four to six weeks of starting treatment in 10 out of 604 patients (1.6%) on MDT for leprosy treated at Rajah Muthiah Medical College Hospital, South Arcot District, Tamil Nadu State during the period 1995 - 1998. Patients developed either maculo papular rash or exfoliation along with fever and lymphadenopathy. Abnormal liver function tests was noticed in 50%. The patients with dapsone syndrome were treated with corticosteroids after withdrawing dapsone. There was complete resolution of skin lesion and other symptoms.