SummaryCreatinine, calcium (Ca), phosphate, immuno-reactive parathyroid hormone (i PTH) and calcitonin (i CT) blood levels were measured before and after haemodialysis (HD) in 24 patients submitted to regular dialysis treatment, and in the days following successful renal transplantation (RT) in other patientsi PTH and i CT levels were elevated before HD; the rise of plasma Ca following HD was accompanied by a decrease in i PTH (P<0.001), whereas i CT was increased, though not significantly.The levels of i PTH and i CT, elevated before RT, returned to normal after RT, together with creatinine and P levels; a rejection after some days in 2 patients was followed by a rapid increase in i PTH and i CT levels. One patient who underwent subtotal parathyroidectomy 281 days after RT because of persistent hypercalcaemia and high i FTH levels is also presented.