To investigate in vivo effect of radiofrequency ablation (RFA) on swine long bones and the repair process. RFA was performed in six swine at the end and middle part of the tibia or femur. After RFA, radiological examinations were performed, and the swine were killed immediately and at different time points post-RFA for histopathological examination. All swine had successful RFA. The RFA-induced elliptical necrotic area ranged from 3.81-5.24 cm(2) (mean 4.08 +/- 0.73 cm(2)) at the bone end but 5.60-8.98 cm(2) (mean 7.58 +/- 1.41) at the middle part immediately after RFA until 10 days, with the necrosis area significantly smaller (P = 0.000) at the end than at the middle. RFA only damaged the cortical bone slightly (0.01 cm thick) with no damage to the soft tissues outside the compact bone at both the end and middle. Surrounding the elliptic pale zone of coagulative necrosis was a narrow brown band of hemorrhage and inflammatory exudate. From day 10 until week 12, tissue proliferation and repair became increasingly apparent, with proliferated granulation, fibrous tissue, and fresh and mature bone trabecula. RFA can quickly and effectively destroy the cancellous bone tissue without affecting the cortical bone and activate bone remodeling.