Ascending cholangitis after portoenterostomy for biliary atresia often leads to significant morbidity. The long-term prognosis also involves recurrent and frequently recalcitrant bouts of cholangitis. Attempts at prophylaxis with use of oral antibiotics are frequently unsuccessful. The authors describe three patients who, after successful portoenterostomies, were plagued with recurrent bouts of cholangitis, despite the use of a variety of antibiotics. The authors instituted oral neomycin as prophylaxis and nearly eliminated this serious complication.