A 48-year-old woman underwent total parathyroidectomy with autotransplantation into the left forearm due to secondary hyperparathyroidism. Recurrence of hyperparathyroidism was observed 5 years later. B-mode high-resolution ultrasonography of the left forearm demonstrated an ill-defined hypoechoic lesion. Frequency- and amplitude-encoded Doppler sonography revealed marked hypervascularity, which was diagnostic for graft hyperplasia in association with the history of the patient. These findings were confirmed by scintigraphy and histological examination of the excised graft.