Intestinal obstruction is a rare cause of acute abdominal pain during pregnancy. We reviewed and analyzed the medical records of four pregnant women with intestinal obstruction, treated at the Department of Surgery in the Kaohsiung Medical University Hospital during a period of 19 years, between June 1984 and December 2002. Their ages ranged from 22 to 35 years (mean, 28 yrs). Three cases had had prior lower abdominal surgery. Adhesion was the unique finding in all four patients during the operation. Enterolysis was needed to release the intestinal obstruction in three of the patients; the fourth required resection and anastomosis of the ileum as a result of volvulus. Premature labor was prevented with tocolysis in two patients. The results of this study lead us to emphasize the importance of close observation and early surgery to avoid intestinal strangulation if a pregnant woman who develops intestinal obstruction has an old surgical scar on her abdomen. Premature labor may be avoided with tocolysis.