The diagnostic procedures recommended for diabetic neuropathy are rather complex and there is the risk that they may be applied only in highly specialized research centres and not in other more basic health service centres that recruit large numbers of diabetic patients. This consideration highlights the need for rapid and precise diagnostic procedures for the screening and follow-up of diabetic patients. In this paper we describe a simplified diagnostic protocol for distal polyneuropathy (DP), which is the most common form of peripheral neuropathy associated with diabetes. We performed an electroneurographic examination (ENG) based on a five-nerve evaluation in 204 diabetic subjects, and took it as the standard. Its reproducibility preliminarily assessed with a test--retest evaluation was 100%. DP was found in 47 of the 204 diabetic patients on the basis of an alteration in at least two nerves. Other clinical parameters, including a questionnaire on symptoms, a clinical neurological examination (NE), and the vibration perception threshold (VPT) were evaluated. The variability coefficient was not significant for all clinical parameters in a selected group of diabetic patients (questionnaire = 21.2%, NE = 5%, VPT = 16.5%). The sensitivities and specificities of the questionnaire, NE, and VPT in comparison with ENG were 87% and 60% for the questionnaire, 94% and 92% for NE, and 64% and 97% for VPT, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)