We experimentally studied the effects of H2 receptor blockers (ranitidine) on bacterial translocation (BT) in 42 male albino rats. Sham group (Group I, n = 12 rats) were exposed to 21 degrees C water while Burn group (Group II, n = 15 rats) and Ranitidine group (Group III, n = 15 rats) were exposed to 95 degrees C hot water for 10 seconds to produce a full thickness burn in 30% of total body surface area. 300 mg/kg ranitidine was administered to Group III starting immediately after the burn injury. Rats were sacrificed on the fifth postburn day. Sham group gained weight while groups II and III had significant weight loss. Gastric pH increased with the administration of ranitidine. Both gram negative and total number of bacteria were found to be reduced in cecal stool cultures in ranitidine group. Significant increase in BT was observed in Group III, and translocating bacteria were found to be different in burn and ranitidine groups with a final conclusion that administration of ranitidine changes intestinal ecological equilibrium and promotes BT.