Dipeptidyl peptidase-4 (DPP-4) inhibitors were first approved in Japan in 2009, and are rapidly becoming a common treatment option for type 2 diabetes because of their safety and effectiveness, especially for Asians including Japanese. We recently encountered a patient with type 2 diabetes and fever that was possibly attributable to treatment with alogliptin, a DPP-4 inhibitor. The diagnosis of drug-induced fever due to alogliptin was based on the resolution of the patient's fever after the discontinuation of alogliptin, the recurrence of fever after re-exposure to alogliptin, relative bradycardia, and a positive drug lymphocyte stimulation test result. Physicians should consider the possibility of drug-induced fever when pyrexia of unknown origin occurs in patients who are being treated with DPP-4 inhibitors.