Through-and-through wire stay sutures of stainless steel were used to reinforce the closure of the abdominal incision in 835 patients, mostly after operations on the upper abdomen. In 893 other patients who had mostly lower abdominal incisions stay sutures were not used. In each of these 2 groups there were 3 cases of dehiscence. The incidence of this complication was about the same (0.36% and 0.33%) in the two groups. This is considered significant because several factors make for weakness of the abdominal wall after incisions in the upper abdomen. The results are therefore interpreted to mean that the stay sutures used for closure after upper abdominal operations appreciably reduced the danger of dehiscence.