Background: obesity continues to be a major public health problem, as defined by a body mass index (BMI) ≥30 kg/m2 . Obesity has been associated with an increased hazard ratio for all-cause mortality, as well as significant medical co-morbidity. Indeed, obesity is not only a chronic medical condition but should be regarded as a bona fide disease state. Objective: the study aimed at correlation between the operative gastric volume reduction and body weight reduction after surgery. Patients and Methods: our study included 30 cases; all were overweight/obese individuals. There were 20 females and 10 males. All patients underwent MSCT abdomen with oral contrast. Post processing in form of multi-planner reformatting and 3D reconstruction was performed to all cases before and 3 months after sleeve gastrectomy. Results: collection and correlation of preoperative and postoperative data, revealed that the percentage of operative gastric volume reduction ranged between 76% and 98% with mean value of about 84%, while the percentage of body weight reduction ranged between 7% and 24% with a mean value of about 15%. The correlation between the body weight and gastric volume measured preoperative in the studied patients was found to be insignificant, which means that the stomach volume doesn't have a direct impact on body weight. Conclusion: MSCT volumetric study of the stomach is the gold standard imaging technique for evaluation of the gastric size in the preoperative and postoperative states in the context of bariatric sleeve gastric surgery.