To explore the frequency of F-wave and H-reflex alterations in recently diagnosed type 2 diabetes mellitus patients and to determine if the alterations are dependent on the levels of glycemia.A cross-sectional study was carried out on 50 asymptomatic patients, with a mean age of 45.4±9.8 years and a disease evolution of less than 10 years. Patients were classified as either normoglycemic (7 mmol/L; n=20) or hyperglycemic (7 mmol/L; n=30). H-reflex (HR), F-wave (FW), and nerve-conduction measurements (NCM) between the diabetic and non-diabetic (control) groups were compared.The H-reflex was absent in 22% of the patients, while the M-component of this reflex was altered in 58% of patients. The F-wave was altered in 12% of the patients. The motor nerve compound action potential showed a diminution in amplitude (26% of patients, n=13), area (32%, n=16), and conduction velocity (20%, n=10). No positive correlation between glycemia levels and the above alterations was found.This study demonstrated that asymptomatic diabetic patients showed a high incidence of subclinical neurophysiological abnormalities.