Background:  Laparoscopic  sleeve  gastrectomy  (LSG)  has  increased  in  popularity  as a definitive bariatric operation. There are no available data in the literature reporting the results regarding the evolution of the size of the gastric tube at middle- or long-term follow- up correlated to the regain of weight or re-increase of the BMI. Gastric capacity can increase late after sleeve gastrectomy even after performing a narrow gastric tubulization. It is very important to measure objectively the residual gastric volume after sleeve gastrectomy and its increase in order to determine the late clinical results and to indicate the eventual strategy for retreatment. A plain multi-slice abdominal CT with 3D volume rendering image can measure the residual gastric pouch volume, and give details about the anatomy of the residual gastric volume after sleeve gastrectomy. Patients and methods: From June 2013 till June 2015, 50 morbidly obese patients with a mean BMI of 46±9 underwent laparoscopic sleeve gastrectomy (LSG) at Ain Shams University hospitals. A plain multi-slice abdominal CT with 3D volume rendering image was done one and six months after surgery. Results: 50 obese patients candidate for laparoscopic sleeve gastrectomy were enrolled in our study. There were forty women and ten men with a mean age of 39 years (18–60). Female: male ratio was 80:20. BMI was 46±9 (range: 40-58) kg/m2, with mean body weight 135(105-165) kg. Excess weight loss was achieved after 3, 6, and 12 months after LSG was 23.7±7, 39.9±14, and 55.9±17%, respectively. Multi-slice plain abdominal CT volumetry was done 1 and 6 months postoperative which showed a mean gastric volume of 106±20 ml one month postoperatively and increased to 167±20 ml after six months. Conclusion: A plain multi-slice abdominal CT with 3D volume rendering image to calculate residual gastric pouch after LSG is a noninvasive, relatively accurate method measuring the residual gastric pouch volume after LSG and provides that after 6 months there is no significant correlation between residual gastric pouch volume increase and EBWL.