We are reporting a case of molluscum contagiosum in a 3-year-old boy who showed a good response to diphenylcyclopropenone (DPCP) immunotherapy. The lesions were multiple, 2 to 7mm in size, centrally umbilicated, normal skin-colored papules of 7 months' duration which were distributed on the penoscrotal area, extremities and trunk. In spite of several treatments using extraction and curettage, new lesions developed continuously. The patient was sensitized with 0.1ml of 1% DPCP solution in acetone on his right shoulder and there-after challenged with solution of varying concentrations (0.05 to 0.1%) on his left shoulder once or twice a week to maintain a mild eczema. Clinical improvement was noted 1 week after sensitization and almost all of the lesions cleared after 8 week's treatment.