Spontaneous bacterial peritonitis is defined by a positive ascitic fluid bacterial culture and an elevated ascitic fluid absolute polymorphonuclear count (≥250 cells/mm3) without an evident intra-abdominal, surgically treatable source of infection. Transient ascites is well documented in patients with extrahepatic portal venous obstruction but spontaneous bacterial peritonitis complicating extrahepatic portal venous obstruction is extremely uncommon. The postulated reasons for the low incidence of spontaneous bacterial peritonitis in extrahepatic portal venous obstruction includes: lower incidence of ascites; intact hepatic reticuloendothelial system; and a relatively high ascitic fluid protein content. Here we report two cases of spontaneous bacterial peritonitis complicating extrahepatic portal venous obstruction.