Short bowel syndrome (SBS) is characterized by the malabsorption of nutrients and fluids that occurs after major intestinal resection, resulting from an adaptation process that begins immediately to increase the mucosal surface area and absorption. Certain nutrients and trophic factors are widely used to increase intestinal adaptation following massive intestinal resection. The efficacy and benefits of glutamine on the intestinal adaptation process is still controversial. This study was conducted to determine the effects of parenteral glutamine administration on intestinal adaptation in a rat model of SBS. Fourteen male Wistar rats were divided into two groups; all 14 underwent 75% small bowel resection. Within each group, rats were assigned to 14 days of treatment with subcutaneous glutamine (0.3 g/kg/day) or isotonic saline daily. Weight changes and histological intestinal adaptation parameters (mucosal thickness, villus height, and crypt depth) were measured. Non-mucosal intestinal changes were evaluated by intestinal fractioned collagen analysis. All rats initially lost weight and began to gain weight postoperatively; however, they did not reach their preoperative weights during the experiment and there was no significant difference between the groups. Histological adaptation parameters were significantly increased after 75% intestinal resection in both groups compared to paired native samples (P<0.01); although the percent of increase was slightly higher in Gln group, no significant difference was detected between the two groups. Fractioned-collagen amounts were found to be similar between groups. The results indicated that parenteral glutamine administration alone does not improve the intestinal adaptation process after massive intestinal resection in rats.