A 15-20% negative appendix rate at emergency appendectomy is considered compatible with appropriate aggressiveness of approach for avoidance of perforation and heightened morbidity rate. But the morbidity rate after negative exploration has been estimated as high as 15%. We compared the morbidity rate after emergency appendectomy among patients with acute appendicitis with that in patients with nonacute appendiceal pathology or with normal appendix. Local septic complications (wound infection and/or intraabdominal abscess) were significantly more common in perforative appendicitis than in nonperforative or in cases without appendicitis. Excluding perforative appendicitis, the incidence of such complications did not differ significantly between the other diagnostic groups. The incidence of other complications was evenly distributed among all groups. A scoring system--possibly computer-aided--taking into account predictive factors in appendicitis, combined with careful in-hospital observation, would probably reduce the negative exploration rate in suspected acute appendicitis without increasing the perforation and morbidity rates.