OBJECTIVE Our goal was to determine if autologous fibrin tissue adhesive derived from the precipitation of fibrinogen using a combination of ethanol and freezing, could be used to completely close both simple and complex fistulas-in-ano. METHODS A 26-patient pilot study was performed in which 100 ml of a patient's blood was drawn 90 minutes before surgery. Autologous fibrin tissue adhesive was prepared. In the operating room the patient underwent an examination under anesthesia, and the primary and secondary fistula tract openings were attempted to be identified. The fistula tract was curetted, and autologous fibrin tissue adhesive was injected into the secondary fistula tract opening until fibrin glue was seen coming from the primary opening. A petroleum jelly gauze was then applied over the secondary opening, and the patient was sent home. Follow-up visits were scheduled for one week, one month, three months, and one year later. RESULTS Twenty-six patients received autologous fibrin tissue adhesive fistula injections, with a mean follow-up of 3.5 months. Initial results were encouraging. Twenty-one of 26 patients (81 percent) had successful initial closure of their fistulas. Two of five failures were injected a second time, and one closed, giving an overall successful closure rate of 85 percent (22/26 patients). Of five patients who failed, mean time to failure was 3.8 weeks. In addition, there was no evidence of infection or complications related to the procedure. CONCLUSIONS Our initial results are optimistic and require further support through longer follow-up data. Fibrin glue treatment of anorectal fistulas offers a unique mode of management that is safe, simple, and easy for the surgeon to perform. By using autologous fibrin tissue adhesive the patient avoids the risk of anal incontinence and the discomfort of prolonged wound healing which may be associated with fistulotomy.