To explore the likelihood of resolution of diabetes postoperatively. Besides, we would like to determine the risk factors associated with development and prognosis of diabetes. All patients in our hospital undergoing surgical removal of pheochromocytoma (PHEO) from 10 October 2010 to 21 July 2017 were retrospectively analyzed to determine those with preoperative diabetes. Preoperatively demographic data and information on diabetes were recorded. The median follow-up was 45.2 months. Finally, 67 (36.2%) patients were with diabetes among 185 patients undergoing surgery. Furthermore, 47 patients had complete follow-up. And 37 (78.7%) patients had improvement of diabetes after resection of PHEO. In details, 29 (61.7%) patients had complete resolution. Older patients were more likely to develop diabetes, and symptomatic patients with longer course of PHEO were also more susceptible to preoperative diabetes. Elevated body mass index (BMI) was a risk factor of persistent diabetes postoperatively after surgery. 36.2% of PHEO patients might be with preoperative diabetes mellitus. Older patients were more likely to present diabetes preoperatively. And the increasing length of PHEO course might be another risk factor on developing diabetes preoperatively. Resection of tumors improved diabetes in 78.7% of patients, with resolution in 61.7%. Patients with higher BMI might need treatment for diabetes postoperatively. Copyright © 2019. Published by Elsevier Taiwan LLC.