We have reported the cases of two patients who had acute pylephlebitis associated with portal vein thrombosis and septic hepatic emboli as a result of right colonic diverticulitis. Although rare, pylephlebitis is a treatable but often lethal complication of intra-abdominal sepsis. Several bacterial pathogens, especially Escherichia coli are associated with pylephlebitis. Early suspicion and prompt antibiotic therapy can lead to resolution of portal vein thrombosis and hepatic abscess formation, resulting in full recovery for the patient. Surgery may not be required. Our two patients received ampicillin--the best first-line drug--until specific antibiotic therapy could be given. Early administration of a broad spectrum antibiotic is essential.