Objective To explore the treatment effect and technical safety of ultrasound-guided microwave ablation for hyperparathyroidism of forearm transplanted autograft. Methods Two patients who had undergone parathyroidectomy with autotransplantation (PTX+AT) and maintenance hemodialysis were diagnosed as having hyperparathyroidism of forearm transplanted autograft based on the increased serum intact parathyroid hormone (iPTH) and aggravated accompanying symptoms. The multimodal high frequency ultrasound was performed to examine the autografts, and ultrasound-guided percutaneous microwave ablation was used to treat the hyperparathyroidism of the patients. Curative effect and symptoms of the patients were observed after treatment. Results Ultrasonography clearly showed the location, number, size and blood perfusion of the parathyroid gland autografts in the forearm of the two patients. After measuring the levels of iPTH in the transplanted tissues of the two patients, one with the lowest iPTH level was retained and the others were treated with microwave ablation, and the ablation treatment was technically successful. In the two patients, 5 and 4 parathyroid gland autografts were ablated and the largest ones were 15 mm×6 mm and 13 mm×5 mm, respectively. The levels of iPTH on the graft side and non-graft side were 87.3 ng/L and 79.6 ng/L, and 66.3 ng/L and 65.2 ng/L after 1 day of microwave ablation, respectively. During the follow-up period of 1 year after microwave ablation, calcium, phosphorus and alkaline phosphatase levels of the two patients were decreased and remained stable, bone and joint pains were relieved, and no numbness or abnormal movement of fingers and wrist joints were found in the transplanted side. Conclusion Hyperparathyroidism of forearm transplanted autograft can occur after PTX+AT. Microwave ablation is effective and safe in the treatment of the hyperparathyroidism.