The viability of osteochondral grafts following cryopreservation at various temperatures (- 20°, - 70°, - 196°), and by additional application of cryoprotectants, with duration of storage up to 3 months, was studied with the help of "S autoradiography. All cryopreserved grafts were proved to be nonvital, irrespective of the freezing technique used, by the failure to take up 35S. Nonvitality of the grafts seems to be the basic reason for the osteoarthrosis of both graft and host tissue that is seen following midterm and long-term periods of observation in animal experiments.