Balanitis xerotica obliterans was studied in 48 fully developed and 6 early cases in children aged 2-15 years. It occurred in 9% of 100 consecutive circumcisions for all, including religious, reasons and in 19% of 232 other circumcisions for disease of the prepuce and penis. Seven cases developed after surgery for hypospadias. The boys nearly always presented with inability to retract the prepuce; half also had discomfort after micturition, and a quarter had obstructive signs, usually minor. At surgery, half had involvement of glans or meatus, previously considered rare in childhood, 3 requiring meatotomy. The condition, once seen, was easily recognized clinically as well as microscopically. The early cases, characterized by focal narrow hyaline edematous zones in severe diffuse chronic balanitis, suggest that the condition may be an inflammation in which the usual increased permeability of small vessels in inflammatory reaction is accentuated in a loose vascular region.