It has been suggested that "renal mass dosing" may affect graft evolution. Between 1993 and 1999, 43 children, aged 4-17 years, received 43 pediatric cadaveric grafts. The ratio between graft volume (calculated by ultrasound within the first 24 h from transplantation, by ellipsoid formula) and the recipient's body surface area (BSA) ranged between 14.1 and 110 ml/m(2). Three groups were identified: group 1, 14-29 ml/m(2) (13 patients); group 2, 30-39 ml/m(2) (16 patients); group 3, 40-110 ml/m(2) (14 patients). As a consequence of the different renal volume increments in the three groups during the first year after transplant, no differences in the absolute renal volume were observed at the end of follow-up. The average follow-up was 38 months (range 12-80). In the 37 routine graft biopsies, performed on average 13 months after transplantation and with more than five glomeruli, maximum mean glomerular diameters were mostly above normal values. There were no significant differences among the three groups. At the end of follow-up,the three groups did not differ in microalbuminuria, proteinuria, glomerular function or in incidence of hypertension. From this retrospective study, we conclude that the very wide range of renal mass dosing did not cause differences in medium-term graft evolution. A longer follow-up will be necessary to ascertain the possible influence of disproportion between pediatric donors and recipients, on a long-term graft outcome.