The concept and technique of cryosurgery in the treatment of benign and malignant bone tumors are presented. Cryosurgery extends the margin of curettage and makes it equivalent to wide resection. Compared with other techniques, cryosurgery with composite fixation not only preserves joint function, but also significantly decreases the rate of local tumor recurrence. Although a relativelysimple procedure, cryosurgery can cause a significant morbidity if performed inappropriately. Effective and safe procedures must follow these consecutive steps: (1) adequate exposure of the tumor; (2) meticulous curettage and burr-drilling; (3) soft tissue mobilization and protection before introduction of liquid nitrogen to the tumor cavity; (4) internal fixation of the tumor cavity; and (5) protection of the operated bone throughout the healing period.