The potent and selective dipeptidyl peptidase-4 inhibitor vildagliptin improves glycemic control in patients with type 2 diabetes through incretin hormone-mediated increases in both α- and β-cell responsiveness to glucose. We conducted a prospective, open-label, parallel group, controlled study of 51 patients with type 2 diabetic patients undergoing hemodialysis (HD) during the 24-week study period. Patients were assigned to two groups: the vildagliptin group (n = 30) and the control group (n = 21). Vildagliptin was administered at 50 mg/day for the first 8 weeks. Then doses were titrated by dose-doubling to a maximum of 100 mg/day if hemoglobin A1c (HbA1c) or glycated albumin (GA) target levels had not been reached. No vildagliptin was administered to the controls. The average final dose of vildagliptin was 80 ± 5 mg daily. After 24 weeks, vildagliptin had decreased average HbA1c levels from 6.7 % baseline to 6.1 %, average GA levels from 24.5 % baseline to 20.5 % and average postprandial plasma glucose levels from 186 mg/dL baseline to 140 mg/dL (all p < 0.0001). In the control group, we observed no such changes. Vildagliptin efficacy did not differ according to age or body mass index, but the GA reduction was significantly greater in the anti-diabetic agents-naïve group. Furthermore, in patients with higher baseline GA levels, a higher vildagliptin dosage was required to produce a noticeable effect. No serious adverse effects such as hypoglycemia or liver impairment were observed in any patient. Vildagliptin was effective as a treatment for diabetic patients undergoing HD.