To evaluate the outcome of asymmetrical complete excision of pilonidal sinus with simple primary closure without using drains or tension sutures. Prospective study. Teaching hospital, Jordan. 46 patients with chronic pilonidal sinus treated between November 1994 and October 1998 by excision of the sinus down to the sacrococcygeal fascia and simple primary closure of the wound without tension sutures or drains. Patients stayed in hospital for 48 hours and postoperative pain was minimal. Complete healing was achieved in 41 patients (89%) after a mean follow up period of 36 months (range 12–60). Two patients (4%) developed recurrent sinuses and in three (7%) the wound broke down. All the patients who healed completely were back to work within three weeks of the operation. Excision and simple primary closure is a cost-effective way of treating chronic pilonidal sinus.