The effects of cryonecrosis in rat kidney after single and repeated local freezing were studied by morphological and cell kinetic methods. Shortly after single and repeated cryolesions a well-demarcated coagulation necrosis developed which was replaced by granulation tissue. 4 weeks after the second freezing only a small fibrous scar was visible. Cell analysis revealed no significant differences between single and repeated cryolesions. Autoradiographically, however, it was shown that the labelling index of fibroblasts in the granulation tissue was higher after repeated than after single cryolesions. The proliferation maxima of epithelial cells were delayed for 24 h. After 4 weeks the cell proliferation again had reached normal values. Hardly any differences between wound healing after single and after repeated cryolesion were found. Thus, repeated cryosurgery is advisable and no complications should be expected.