Treatment of anorectal suppuration includes timely and sufficient surgery. So later complications like fistula-in-ano can be ruled out.In this prospective study the data of 324 patients who had been operated because of an anorectal suppuration were examined. 38,6% of these abscesses were located in the perianal tissue, 34.6c~ in the intersphincter space, 19.4% in the ischiorectal fossa and 7.4% in the supralevator space. Only in 25.6% patients who were operated an anal fistula was proved. In ischiorectal abscesses we found fistuta-in-ano within 47.6% of the patients, in most cases trans-~nd suprasphincteric fistulas. 62.1% of these patients did not need further interventions. Sixteen of 45 intraoperative diagnosed trans-and suprasphincteric fistulas did not need further operative interventions (35.6%). At 7.7% later diagnosed fistulas had to be treated operatively, 9.6% of the patients developed a new suppuration.