Fifteen patients who developed a persistent perineal sinus after excision of the rectum and eight patients with a perineal fistula appearing after treatment of perineal abscesses were treated with instillation of fibrin adhesive to close the sinus or fistula. In 12 patients, the sinus tracts or fistulas were completely and permanently closed (52 percent). In five patients (22 percent), the fistulas healed after two or three attempts, while, in six patients (26 percent), the method failed to provide lasting closure. The method seems to be a valuable alternative in the treatment of a persistent, long and narrow perineal sinus or fistula.