Eighty consecutive neurological ambulatory patients with various symptoms are presented. All patients with a history of diabetes or alcoholism were excluded. The group was composed of 54 females and 26 males ranging in age from 16 to 67 years. Neurological examination showed at least one peripheral abnormal finding in all patients. Absence of Achilles reflexes, impairment of tactile and vibratory sensibility in the distal portions of the legs and dysesthesia were the most frequent alterations. All patients showed normal fasting blood sugar and were submitted to the oral glucose tolerance test. Some evidence of abnormal glucose tolerance was present in 41 patients (51.25% of the entire group). Thus, we suggest that polyneuritis, misinterpreted as late complication, is indeed an integral part of the syndrome of diabetes and may be its very first objective sign. In conclusion, it is assumed that all patients with evidence of objective polyneuritis should be thoroughly tested for abnormality of glucose tolerance.