The purpose of this study was to compare the circumference and skinfold thickness of upper and lower limb and the leg strength of the casted limb with those of the normal limb after removal of a leg cast. The subjects for the study were orthopedic patients who had had long and short leg casts or splints due to tibial, fibulal, metatarsal, calcaneus fracture or ankle sprains. The subjects were divided into two groups, those who had the cast on for less than 40 days and those for over 41 days. Circumference and skinfold thickness of the upper and lower limb on the side on which the cast was ap-plied were compared with those of the contralateral side after removal of the cast. Circumference and skinfold thickness of the upper and lower limb, and leg strength for those in a cast for under 40 days were compared with those of over 41 days for both the side to which cast was applied and the contralateral side. Measurements were made after removal of the cast. Skinfold thickness was measured by fat caliper, circumference was measured by tape and lower extremity strength was determined with flat foot pressing on an electronic digital health meter in the sitting position. The results can be summarized as follows : 1. The circumference of the upper and lower leg on the side on which the cast was applied, when measured after the cast was removed, were significantly less than those of the normal side, 93.88%, 93.11% each. 2. Skinfold thickness of the quadriceps and gastrocnemius on the side on which the cast was applied were significantly less than those of the normal side when measured after removal of the cast, 85.98%, 82.85% respectively. 3. Leg strength on the side where the cast was applied was significantly 1ss than that on the normal side, 60.20%. 4. There was no difference in the circumference of upper and lower limbs, skinfold thickness or leg strength on the side where the cast was applied between the group which had the cast applied for under 40 days and the group that had it applied for over 41 days. 5. The circumference of the upper arm and lower leg on the normal side for the group that had the cast applied for over 41 days was significantly greater than the group that had the cast application for under 40 days. T ere was no difference between the two groups in the circumference of the forearm and upper leg, skinfold thickness and leg strength in the normal side. From these results, it may be concluded that muscle atrophy was apparent in the casted limb compared to the normal limb, and the circumference of the upper arm and lower leg, and leg strength on the normal side increased after removal of the cast in the group which had the cast on for more than 41 days.