Multiple fixation techniques for tibiotalocalcaneal arthrodesis have been introduced. The interlocking intramedullary nailing for tibiotalocalcaneal osteoarthritis with osteoporosis permits excellent internal fixation. We had two retrograde interlocking intramedullary nail fixation for tibiotalocalcaneal arthrodesis. One patient is chronic infectious osteoarthritis of the ankle and subtalar joints. And the other is non-union of the distal tibia with arthrofibrosis of the ankle and subtalar joints. Two patients also had osteoporosis due to long immobilization. The follow up period were 12 and 22 months respectively. The leg and foot is aesthetically pleasing and the musculature around the ankle and foot is maintained in the normal balanced position after the tibiotalocalcaneal fusion. So, we believed that the interlocking intramedullary nailing is an excellent treatment method for tibio talocalcaneal arthritis with osteoporosis.