C-peptide, as a marker for pancreatic beta cells function, and somatostatin (SS) in plasma of obese males (n = 15) and a corresponding normal-weight control subjects (n = 10) are studied in this work. Fasting plasma SS and serum C-peptide are significantly higher in obese vs lean group, this can be explained by hypertrophy of both D- and B-cells of the pancreatic islets reported by other investigators. Post-prandial plasma SS in insignificantly increased in obese vs the control group wheres the increase in C-peptide levels is significant suggesting unequal response of B- and D-cells to meal in the obese group. We concluded that circulating SS may play important role in development of obesity. Hyperinsulinaemia, documented in obesity may be due to hypersecretion of insulin (marked by rise of serum C-peptide in this work), and this may contribute to increased somatomedin-C in obesity.