Objective: Weight loss induced by the complete resection of insulinoma is controversial in overweight patients. The study sought to explore postoperative weight loss and metabolic changes in overweight insulinoma patients.Methods: A retrospective study was conducted to review the follow-up data of insulinoma patients with a BMI ≥25kg/m2 who underwent complete lesion resection between May 2010 and May 2015. Body mass index (BMI), weight loss (WL) and percentage weight loss (%WL) were main outcomes.Results: Fifty-one patients were included with a median follow-up of 28 months. The BMI at 3 months, 1 year, 2 years and 3 years postoperatively were significantly lower than the preoperative BMI values (p < .01). The WL% was 12.9% at 3 months postoperatively without significant changes throughout the 3-year follow-up. WL and the %WL were significantly higher in the high BMI group (BMI≥ 27.5 kg/m2). Multivariate analysis indicated that higher initial BMI was associated with increased weight loss (p = .001). 63.8% of patients with hypertension recovered and improved sleep quality was evident in all patients with obstructive sleep apnea syndrome within 1 year postoperatively.Conclusions: Weight significantly decreased postoperatively in overweight insulinoma patients, which was more evident in patients with higher BMI and metabolic comorbidities were largely improved.