We have assessed the fate of amyloid bone cysts after a successful renal transplantation in 5 patients who had been on dialysis for 7 to 15 years. The size of 34 cysts, typical of amyloid osteoarthropathy, was monitored on annual X-rays for 29 to 75 (mean 47) months after TP. In sharp contrast to their progression during dialysis, cysts did not increase in size and no new cysts appeared during follow-up. However, despite a successful graft, none of the 34 cysts regressed significantly. The stability of the bone cysts may reflect either the poor solubility of the beta 2-m amyloid deposits or the limited accessibility of bone deposits to lytic factors. A longer follow-up will perhaps be necessary to document a significant regression of the cysts. Strikingly, transplantation resulted within a few days in an almost complete relief of articular complaints; in the absence of evidence of amyloid regression, this probably reflects the anti-inflammatory effect of steroids.