Objectives: Persistent secondary hyperparathyroidism is common after successful kidney transplant, with concomitant hypercalcemia and hypophosphatemia potentially leading to reduced graft survival and increased cardiovascular risk. Cinacalcet, a calcimimetic agent that activates the calcium-sensing receptors in parathyroid glands, is a therapeutic option. In this study, we assessed the long-term treatment effects of cinacalcet for a period of up to 5 years in a cohort of kidney transplant recipients. Key words: Hypophosphatemia, Kidney function, Renal transplant IntroductionSecondary hyperparathyroidism is a frequent complication of end-stage renal disease. After successful kidney transplant, secondary hyperparathyroidism usually remits; however, it persists in 30% to 50% of patients 1 year after transplant. [1][2][3] Risk factors for the development of persistent secondary hyperparathyroidism after kidney transplant include the duration of renal replacement therapy and the severity of secondary hyperparathyroidism before transplant. 1,4 In kidney transplant recipients, persistent secondary hyperparathyroidism is characterized by elevated serum parathyroid hormone (PTH) and/or hypercalcemia and hypophosphatemia. 2,5 Parathyroid hormone increases bone resorption, inhibits fractional renal calcium excretion, and promotes calcitriol production by the kidney allograft. Calcitriol, in turn, increases calcium absorption from the intestinal tract.