Aim of this investigation was to correlate basal beta cell function and insulin sensitivity in healthy man. A group of 10 healthy subjects with normal body weight and glucose tolerance was studied. Insulin sensitivity was assessed by glucose disappearance rate after insulin injection (0.1 IU/kg body weight). Beta cell secretion rate was estimated by the evaluating of fasting C peptide circulating levels. A positive and significant relationship was observed between fasting C peptide concentrations and coefficients of insulin sensitivity (r = 0.694, p < 0.05). We conclude that in healthy man basal beta cell secretion rate plays an important role in determining the peripheral sensitivity to insulin. In particular, hormone sensitivity is directly proportional to pancreatic hormone production in basal condition.