The clinical and radiological features of acute large-bowel pseudo-obstruction occurring in 13 patients over a 7-year period are reviewed. Clinical features included atypical signs and symptoms of large-bowel obstruction and serious concomitant illness, including trauma in 10. The predominant radiological features were gross colonic dilatation, scant fluid levels, a gradual transition to collapsed bowel and a normal gas and faecal pattern in the rectum. Correct diagnosis was established by plain film and/or barium enema examination in the majority of cases (nine out of the 13). In the remaining four cases the diagnosis was made at laparotomy, although review of the radiographs suggested that the correct diagnosis could have been made pre-operatively in three. Instant barium enema is recommended in doubtful cases to rule out distal obstruction. Prompt recognition of the condition, with daily monitoring and conservative management, should eliminate unnecessary surgery and minimise the risk of caecal perforation.