The development of a fistula is a serious postoperative complication. Conservative medical treatment with total parenteral nutrition, skin care and intensive infection control usually succeeds in closing fistulas (60 to 75 percent), but the treatment is of long duration (two to three months), high cost and high morbidity related to prolonged hospitalization. We have used octreotide, a long half-life stomatostatin analog, in 40 patients from two European university centers with postoperative enterocutaneous fistulas. Twenty-two patients had low fistula output and 28 patients had high fistula output. Spontaneous closure was achieved in 77.5 percent of the patients after a mean of 13.6 days. One patient died. Glucose intolerance, which has been reported with stomatostatin treatment of fistulas, was not observed. Previous chemotherapy or radiotherapy or low albumin level (23 grams per deciliter) negatively influenced fistula closure. As an adjunct treatment to primary care (total parenteral nutrition, skin care and infection control), octreotide is efficient in reducing fistula output and accelerating spontaneous fistulas closure.