'On-table' pneumoperitoneum before repair of 'complicated' incisional hernias has been used in eight patients considered to be at high risk of recurrence. In four patients the procedure revealed the presence of occult defects. The procedure was uncomplicated and a primary repair without the need for a prosthetic implant was possible in all cases. Six patients remain well with no sign of recurrence at a median follow-up of 96 months (range 22-120 months). Two patients died from conditions unrelated to the method of repair; acute necrotising pancreatitis on the 10th postoperative day and lobar pneumonia 2 months postoperatively. Peroperative pneumoperitoneum is a simple procedure which obviates the need for a prosthetic implant in selected patients. It is therefore particularly useful in the management of incisional hernias associated with sepsis, stomas or in patients requiring synchronous bowel resection.