A gastrointestinal fistula is a late complication of peptic ulcer disease and forms when gastric resection is inadequate or vagotomy is incomplete or not performed. Such cases are extremely rare and are occasionally reported in the literature. We present a patient with a gastrocolic fistula which developed 7 years after partial gastrectomy due to pyloric stenosis as a sequella of peptic ulcer. Nonspecific clinical symptoms and ambiguous radiographic findings delayed the diagnosis of gastrocolic fistula. The patient was operated; "en bloc" resection of the fistula with partial resection of the transverse colon and stomach supplemented with truncal vagotomy was done. The possible cause of recurrence of peptic ulcer in this patient was that vagotomy was not done during the first surgical intervention. Thus, the gastrocolic fistula became a late complication of the recurrence of peptic ulcer. Diagnostic difficulties in gastrocolic fistulas are presented and surgical management of this complication is discussed.