In a 30-year-old man, a total external pancreatic fistula developed after enucleation of an insulinoma of the head of the gland. The output of the fistula was reduced to some extent by total parenteral nutrition. Much greater reductions of volume were noted during short-term administration of two somatostatin preparations, SMS 201–995 and Somatofalk, for l week consecutively. Although the former showed several advantages over the latter drug, such as absence of an escape phenomenon and of a rebound effect, neither drug caused a closure of the fistula. Spontaneous closure of the fistula occurred after 31/2 months.