Background Diabetic neuropathy is common in diabetes mellitus. The early stage of diabetic neuropathy is often symptomless and difficult to be treated. The aim of this study was to assess the correlation between the results of the sympathetic skin response (SSR) test and the development of diabetic neuropathy, and explore the use of SSR as an objective basis for the early diagnosis of diabetic neuropathy. Methods The latencies and amplitudes of initiation and of the N and P waves were determined by SSR testing of the extremities of 80 diabetic patients and 30 healthy controls. Results The latencies of initiation and of the N and P waves were significantly (P<0.001) longer in diabetic patients than in the controls, while there was no significant difference in the amplitudes (P>0.05). All but two patients (97.5%) demonstrated abnormal SSR in at least one limb. Conclusions SSR can detect early dysfunction of the small sympathetic fibers in people affected by diabetes mellitus, and may be a useful electrophysiological test for the early diagnosis of diabetic neuropathy. Background The aim of this study was to assess the correlation between the results of the sympathetic skin response (SSR) test and the development of diabetic neuropathy, and explore the use of SSR as an objective basis for the early diagnosis of diabetic neuropathy. Methods The latencies and amplitudes of initiation and of the N and P waves were determined by SSR testing of the extremities of 80 diabetic patients and 30 healthy controls. Results The latencies of initiation and of the N and P waves were significantly (P <0.001) longer in diabetic patients than in the controls, while there was no significant difference in the amplitudes (P> 0.05). All but two patients ( 97.5%) expressed abnormal SSR in at least one limb. Conclusions SSR can detect early dysfunction of the small sympathetic fibers in people affected by diabetes mellitus, and m ay be a useful electrophysiological test for the early diagnosis of diabetic neuropathy.