Fifty-three patients treated by surgery for pilonidal sinuses in the sacrococcygeal area during a 2 1/2-year period at The Mount Sinai Hospital of Cleveland were studied. A fourth of the patients were first seen because of an acute episode of infection, and the other patients had chronic lesions. Surgery on an elective basis consisted of 1) excision and primary closure; 2) excision with partial closure of the wound; or 3) marsupialization. Fifty of the 53 patients were followed up for two to three years; the shortest follow-up period was six months. The overall recurrence rate in this group was 6 per cent. It appears that marsupialization results in a better chance for a cure and a shorter period of hospitalization.