Portal vein thrombosis is a very uncommon complication after laparoscopic surgery. Although only one case of portal vein thrombosis has been reported after laparoscopic colectomy, there are several reports of mesenteric vascular occlusion after other laparoscopic procedures. We present a case of portal vein thrombosis in a patient with no other demonstrable hypercoagulable states or risk factors, who underwent an uneventful laparoscopic sigmoid colectomy. Because alteration in coagulation may occur after establishing a pneumoperitoneum, we suggest that heparin prophylaxis may be advisable to avoid these kinds of complications, especially if a past history of coagulable disorders is present.