The diagnosis of malrotation is easily made in the neonatal period, but is often delayed in older patients. Among 82 patients treated for malrotation in this institution, 45 patients presented with symptoms related to their malrotation, seven were diagnosed at exploration for concomitant intrinsic duodenal obstruction, and 30 patients had malrotations discovered as incidental findings at laparotomy or autopsy. Among the 45 symptomatic patients, 25 (56%) underwent surgery in the first month of life, whereas 20 patients (44%) underwent surgery at an older age. In this last group, the mean age at surgery was 51.5 months (range, 2 months to 16 years), the mean age of onset of symptoms was 2 years (range, 0 to 15 years) and the mean delay in diagnosis was 1.7 years. Although bilious vomiting was the presenting symptom among all patients undergoing surgery in the neonatal period, clinical features of older patients included intestinal obstruction (7), chronic abdominal pain (4), malabsorption/diarrhea (3), peritonitis/septic shock (2), solid food intolerance (1), common bile duct obstruction (1), abdominal distention (1), and delayed transit postappendectomy (1). The frequency of midgut volvulus was equal among both groups. Unusual forms of malrotation were more frequent in patients undergoing surgery beyond the neonatal period. In this group there was evidence of chronic venous and lymphatic obstruction with one case of superior mesenteric vein thrombosis and two cases of intestinal gangrene. A Ladd's procedure was performed in all cases and the most frequent postoperative complication was adhesive intestinal obstruction. There were no deaths. Awareness of the unusual presentation in patients who present beyond the neonatal period may help reduce delays in diagnosis and surgical treatment. We believe that laparotomy is indicated in all patients with malrotation, even if they are asymptomatic.