Abstract Surgical treatment of high or complex anal fistulas often renders unsatisfying results. This is the report of the first successful closure of such anal fistula using a special Nitinol clip and applicator, the OTSC® Proctology system (Ovesco AG, Tuebingen, Germany): A 54-year old female patient was suffering from a high transsphincteric anal fistula. After seton drainage of the fistula for ten weeks, the fistula track was debrided using a special fistula brush. After transanal clip release from the applicator, the internal fistula opening was adequately closed by the clip. Eight months after clip closure the fistula had healed and the clip was removed using the OTSC® Proctology Clip Cutter. Fistula closure using the OTSC® Proctology system represents a promising sphincter-preserving minimally invasive procedure.