The main aim of this study is to evaluate the role of blink reflex for early diagnosis of cranial neuropathy in diabetic patients with or without polyneuropathy. Ninety-five diabetic patients were included in the present study for the evaluation of blink reflex. The diabetic patients were divided into two groups according to having diabetic neuropathy or not. Both R1, R2i and R2c latencies in all diabetic patients with or without polyneuropathy were prolonged relative to controls and the differences were statistically significant (p < .001). R1 latencies in diabetic patients with polyneuropathy were prolonged relative to diabetic patients without polyneuropathy and the differences were statistically significant (p < .001). These findings presumably reflect that facial nerve is severly involved in diabetic polyneuropathy. Finally blink reflex is of value in detection of clinically silent intraaxial brainstem functional abnormalities or extraaxial lesions in diabetic patients before peripheral neuropathy.