A clinical study was performed to evaluate the efficacy of the Viscoped Insole as compared with an 1/8-inch PORON medical materials insole in the treatment of lesser submetatarsal hyperkeratotic callosities. Thirty-five patients, ranging in age from 23 through 61 years (average 42 years) were randomly divided into three groups. All three groups initially had debridement of their submetatarsal callosities. In addition to the debridement, the first group (16 patients) wore a Viscoped Insole for 4 weeks. The patients in the second group wore a PORON insole for 4 weeks. The third group did not receive an insole after their debridement and served as the control. There was a significant improvement in the Viscoped group and the PORON group versus the control group (x2 = 40; p < 0.01) as measured by the foot function index. Insole therapy combined with debridement for submetatarsal hyperkeratoses is more effective than debridement alone.