This non-randomised concurrent cohort study conducted in two teaching hospital Departments of Surgery examined the assumption that the benefits of elective laparoscopic upper gastrointestinal surgery would apply to those with generalised peritonitis due to perforated peptic ulcers. It compared 20 consecutive laparoscopic repairs of perforated peptic ulcers with a concurrent group of 16 consecutive open repairs. There were no differences pre-operatively between the two groups. The mean duration of surgery was similar (P = 0.46). There were no differences in the rate of GI tract recovery, but opiate analgesia requirement in the laparoscopic group was significantly less (P < 0.0001). Intensive care was required in three patients in the laparoscopic group (two with renal failure) and two in the open (no renal failure). Two patients in the laparoscopic and one in the open group died. The median duration of stay was five days in the laparoscopic group and six in the open. This comparison shows that the patho-physiological insult of laparoscopy in the setting of generalised peritonitis does not obviously increase the peri-operative risk of organ failure but objective benefits are small