In this paper the authors consider the problem of incisional hernias as late complications of bariatric surgery. After a description of relationships between obesity and incisional hernias they report their experience on this topic, consisting of 56 patients submitted to bilio-pancreatic diversion between March 1989 and September 1991, for surgical treatment of morbid obesity. Incisional hernias developed in 28% of cases. Analysis of some risk factors like infections, epidemiological patterns, materials and techniques used to suture the abdominal wall, has not allowed identification of significant associations with incisional hernias occurrence. Only early reinterventions (3 cases) have always determined a subsequent development of incisional hernias. The authors confirm the close relationship existing between obesity and incisional hernias. They suggest incisional hernia repair to be undertaken once weight loss has terminated and stabilized, and in the absence of other specific or aspecific morbid obesity surgery complications.