From 1967 to 1995, we treated 16 patients with mesenteric venous thrombosis (MVT). Major complaint was abdominal pain, and 13 patients had predisposing factors. One was diagnosed by color Doppler ultrasonography and cured by anticoagulant, 14 were misdiagnosed, 7 died postoperatively, and 8 cured. Early diagnosis lies on predisposing factors, discordance of symptoms and signs, color Doppler ultrasonography, CT, and angiography. Early operation for removing the involved intestine with its mesentery and early application of anticoagulant are essential to decrease the mortality and recurrence.