Mesenteric venous thrombosis, "the great mimicker", is a very rare disorder in pregnancy and the puerperium, particularly when not associated with any pre-existing thrombophilia or autoimmune states. We describe a patient requiring a resection of 150 cm of gangrenous small bowel after uncomplicated elective Caesarean section.The only risk factor for thrombosis was recovery from an elective Caesarean section, a condition classified by the Royal College of Obstetricians and Gynaecologists as "low risk"(1). Death from thromboembolism is the leading cause of maternal mortality(2) and should always be considered with unusual post partum symptoms. Early diagnosis of mesenteric vascular occlusion is difficult and recent evidence suggests that elevated GST isoenzyme may be helpful(3).In all cases of MVT anti-coagulation is the basis of treatment. Patients who are not anticoagulated after surgery have a recurrence rate of 25 per cent compared with 13 per cent of heparinised post-operative patients(4). As no other pre-existing cause for MVT was found, management was with warfarin for 6 months, the oral contraceptive pill was contraindicated and heparin prophylaxis was recommended for future pregnancies.