Purpose: To determine the effect of an orogastric tube for calibration of the gastric pouch on percentage excess weight loss (%EWL) and percentage total weight loss (%TWL) after laparoscopic Roux-en-Y gastric bypass (LRYGB).Material and Methods: A retrospective case-matched control study in 132 patients. Group A (a 40 French orogastric tube was used to calibrate the gastric pouch) was compared to group B (no orogastric tube was used). All other surgical steps were identical in both groups. Postoperative %EWL and %TWL were recorded at 3, 6, 9, 12, and 24 months postoperatively.Results: Baseline characteristics and comorbidities were similar for both groups; a mean age of 43.6 years, 84% of the patients were female and mean initial BMI was 44 kg/m2. At 24 months, 9% of the patients were lost to follow-up. At 1-year follow-up, %EWL and %TWL were 80% and 33.3% in group A versus 70% and 28.6% in group B with p = 0.013 and p = 0.007 respectively. At 2 years, EWL% and %TWL were 79.5% and 32.8% in group A and 67.18% and 28.1% in group B with a p value of 0.019 and 0.001 respectively. The use of a calibration tube, initial BMI, and age predicted the %TWL best with R squared at 30.7%.Conclusion: The use of a calibration tube for creating the gastric pouch may lead to a higher %EWL and %TWL at 2-year follow-up. The standardization of the technique for LRYGB is desirable to achieve the maximum success rate in the surgical therapy of morbid obesity.