OBJECTIVE: This study was designed to evaluate the compressibility of heel pads in patients with diabetes mellitus. METHOD: The subject were twenty control subjects and 20 patients with diabetes mellitus diagnosed at least 5 years previously, over the age of 40. The thickness of heel pads was measured by ultrasonography without pressure and with pressure of 1 kg, 2 kg and 3 kg at the line connecting the second toe and the mid-heel point. The ratio of the thickness of the heel pad with pressure of 1 kg, 2 kg, 3 kg and without pressure, R1 (ratio of the thickness of heel pad with 1 kg and without pressure), R2 (2 kg) and R3 (3 kg), was compared between controls and diabetics. RESULTS: There was no significant difference of heel pad thickness between controls and diabetics without pressure in sole. The diabetics had greater ratio, less compressibility than controls (p<0.05). The ratio of the control group was R1; 0.67+/- 0.07, R2; 0.53+/-0.07 and R3; 0.45+/-0.07, whereas that ratio of the diabetic group was R1; 0.80+/-0.09, R2; 0.68+/-0.09 and R3; 0.58+/-0.09. CONCLUSION: The evaluation of compressibility of heel pad of the patients with diabetes mellitus compared with the control group will help to make a treatment of heel pain or discomfort.