Recurrent abdominal pain in the left fossa often mimicking attacks of subileus is described in a woman aged 48 with extensive adhesions caused by multiple surgical procedures. Repeated examinations with conventional abdominal radiography and barium meals were negative with regard to mechanical intestinal obstruction. A cystic lesion varying in size from 2 to 8 cm in diameter was seen adjacent to the left ovary on repeat US examinations and also on CT. Pain episodes were sometimes correlated to increasing size of the lesion which was finally thought to be either a peritoneal inclusion cyst (fluid trapped between pelvic adhesions) or, as was finally confirmed at surgery, a true ovarian cyst (corpus luteum cyst) similarly trapped.