Background: Sleeve gastrectomy (SG) has been used as a multipurpose surgical procedure for the treatment of morbid obesity. The aim of the study was to analyze gastric morphology and histology at two different time points after SG in rats. Methods: Thirty-five male Wistar rats were fed ad libitum during 3 months on a high-fat diet to induce obesity. Subsequently, 25 diet-induced obese rats underwent either SG (n=12) or a sham operation (n=13). The remaining ten obese animals encompassed the nonoperated control group (Co). Four weeks postoperatively, 15 rats (n05 rats/experimental group) were sacrificed, while the remaining 20 rats were sacrificed after 16 weeks (animals/group; Co=5, sham=8, SG=7) to compare the gastric morphological and histopathological changes over time. Body weight and food intake were regularly recorded. Results: For both time periods, the Co groups exhibited the highest body weight, while the rats undergoing the SG showed the lowest weight gain (P<0.05). Initially, significant differences (P<0.005) in food intake relative to body weight were observed between the Co rats and animals undergoing surgery, which disappeared thereafter. The actual total stomach sizeafter both experimental periods in the SG group was similar to that of non- and sham-operated rats mainly due to a forestomach enlargement, which was more pronounced after 16 weeks. Traits of gastritis cystica profunda characterized by gastric foveolae elongation with hyperplasia and cystic dilatation of the glandswere observed in the residual stomachs of the sleeve-gastrectomized rats. These findings were mostly observed after 16 weeks of performing the SG, although they were also detected occasionally following 4 weeks postoperatively. No intestinal metaplasia was observed. Conclusion: After SG gastric macro- and microscopic changes with functional implications in both the short and long term take place.