A group of 170 patients having functional renal allografts were evaluated at least six months after renal transplantation. They were assessed for symptoms and signs of tendinitis in the Achilles and Supraspinatus tendons. Of the 170 patients, 34 had tendinitis. Four patients (11.8%) had spontaneous rupture of the Achilles tendon one week to 72 months after transplantation. All of the symptomatic patients had received steroids, and 81% of these had been treated with methylprednisolone. Of the asymptomatic patients 89% received steroid and 69% received methylprednisolone. There was a significant correlation between symptoms of tendinitis and the cumulative steroid dose. The number of matching HLA loci of the donor kidney and the length of time on dialysis were also related to the incidence of tendinitis. Unlike a previous study (1) we could not find significant differences between the 34 patients with tendinitis and controls with reference to the levels of serum phosphate, alkaline phosphatase, albumin adjusted calcium, or cholecalciferol therapy prior to transplantation. Our data confirm that tendinitis is surprisingly common in patients after renal transplantation (20.0%).