The dipeptidyl peptidase-4 inhibitor alogliptin (Nesina®, Vipidia®) is approved in numerous countries worldwide for the treatment of type 2 diabetes mellitus. Fixed-dose combinations of alogliptin/metformin (Kazano®, Vipdomet®) and alogliptin/pioglitazone (Oseni®, Incresync®) are also available. This article reviews the clinical efficacy and tolerability of oral alogliptin in the treatment of type 2 diabetes. Results of randomized controlled trials demonstrated that oral alogliptin improved glycaemic control when administered as monotherapy, as dual therapy in combination with metformin, pioglitazone, a sulfonylurea, voglibose or insulin, or as triple therapy in combination with metformin plus pioglitazone. Alogliptin was generally well tolerated in patients with type 2 diabetes and was weight neutral, with a low risk of hypoglycaemia. Results of the large, well designed EXAMINE trial revealed that alogliptin was not associated with an increased risk of major cardiovascular events in patients with type 2 diabetes and recent acute coronary syndrome. In conclusion, alogliptin is a useful option for the treatment of patients with type 2 diabetes.