Up to 11% of all coeliotomies result in incisional hernias, their repair is followed by recurrences in up to 46%. To control the incidence of these complications transverse and oblique incisions with a skin incision of sufficient length should be prefered. At the first operation the abdominal wall should be closed by a single continuous suture with an absorbable material. Non-absorbable materials should be used for hernia repair. The doubling of the facial structures gives no advantage. Alloplastic materials are restricted to problem hernias.