The incidence of clinically significant anastomotic leaks after upper gastrointestinal surgery is approximately 4 % - 20 %, and the associated mortality can be as high as 80 %. Depending on the clinical presentation, the treatment options are surgery, conservative treatment with external drainage, or endoscopic treatment. This report presents 39 cases of clinically apparent anastomotic leaks or fistulas after surgery for upper gastrointestinal cancers that were treated by endoscopy with insertion of fibrin glue alone (n = 24) or with a combination of Vicryl plug and fibrin glue (n = 15). Thirteen of the 15 patients who underwent Vicryl/fibrin treatments showed complete healing of the anastomotic leak or fistula after one to four sessions. Long-term follow-up results are presented. Postoperative upper gastrointestinal fistulas or anastomotic leaks can be managed successfully with low morbidity by means of endoscopic insertion of Vicryl mesh with fibrin glue, thereby avoiding repeated major surgery and its associated risks.