The aim of this study was to examine whether administration of glutamine are able to prevent the NSAID induced bacterial translocation and lipid peroxidation in the rats. The animals with glutamine were fed with L-glutamine for 5 days before diclofenac administration (100 mg/kg orally). 48 hour after diclofenac administration, intestinal permeability, serum biochemical profiles, and malondialdehyde levels of ileum were measured for evaluation of gut damage. Also, enteric aerobic bacterial counts, number of gram-negatives in mesenteric Iymph nodes, liver, spleen and kidney and malondialdehyde levels in liver, spleen, kidney and plasma were measured. Diclofenac caused the gut damage, enteric bacterial overgrowth, increased bacterial translocation and increased lipid peroxidation. Co-administration of glutamine reduced the gut damage, enteric bacterial overgrowth, bacterial translocation and lipid peroxidation induced by diclofenac. This study suggested that glutamine might effectively prevent non-steroidal anti-inflammatory drug induced bacterial translocation and lipid peroxidation in the rat.