In this paper we present results dealing with neopterin levels in the urine of 21 kidney grafted patients during long-term allograft survival. Data dealing with results of urinary neopterin excretion to predict acute cellular allograft rejection during the immediate post-transplant period have been reported previously. The evaluation of patients included a physical investigation and numerous biochemical parameters as described below. We found that neopterin excretion is normal or elevated, but if elevated levels remain stable the prognosis for the allograft seems to be good.