Background Laparoscopic adjustable gastric banding (LAGB) continues to be a valid surgical treatment option to address severe obesity. However, outcomes are varied and can be difficult to predict. Early prediction of suboptimal weight loss following LAGB may enable adjustments to postoperative care and consequently improve surgical outcomes. Therefore, our aim is to investigate the prognostic utility of using early weight loss following LAGB to predict long‐term weight outcomes. Methods Clinical data from patients undergoing LAGB between 2001 and 2007 at a single institution were retrospectively collected and analysed. The data was used to inform a model for predicting long‐term weight loss after LAGB surgery. Percent total weight loss (%TWL) greater than 20% 1 year after surgery was considered a measurement of success since it has been associated with the improvement of comorbidities and increased patient satisfaction. Results The average %TWL 1 year after LAGB surgery was 23.73% (n = 1524, SD = 8.68%). Weight loss of less than 10% in 1 year was a negative predictor of weight loss >20% in 8–12 years (OR = 0.449; p = 0.002; 95% CI = 0.272–0.742). Moreover, weight loss >20% in 1 year was a strong predictor of weight loss >20% in 8–12 years (OR = 5.33; p < 0.001; 95% CI = 3.17–8.97). Conclusion Total body weight reduction of less than 10% 1 year after LAGB surgery suggests a lesser weight loss at 8–12 years. For these patients, targeted interventions would be appropriate to increase the chances of long‐term success.