A retrospective study of the principal causes of mechanical bowel obstruction occurring in Western Turkey between 1979 and 1989 was undertaken. The records of 14,777 operations performed in the general surgery departments of two hospitals were reviewed. Mechanical bowel obstruction occurred in 582 patients. Among the causes of mechanical bowel obstruction, adhesions were most common (44.0 per cent), followed by strangulated hernia (23.9 per cent), volvuli (12.7 per cent) and colonic carcinomas (10.1 per cent). A previous appendicectomy appeared to be the most important cause of adhesions causing mechanical bowel obstruction.