An updated study of the glomerular lesions found in renal grafts in children showed 3 features of interest. 1) In our experience, the incidence of the occurrence of de novo membranous glomerulonephritis (MGN) remains around 9% (48 of 530 grafts). 2) Of the 29 patients we reported in a previous study [Antignac et al. 1988], 18 lost their grafts and 7 received a second graft. Four of these 7 patients recurred de novo MGN on their second graft. Their clinical course is reported in detail. 3) In our population of transplanted children, of the 55 patients who received a second graft, the only recipients who developed a de novo MGN were the 4 patients who had already developed de novo MGN on their first graft. The various factors possibly involved in the pathogenesis of de novo MGN are reviewed. The high incidence of recurrence of de novo MGN indicates that host factors play a major role in the development of this nephropathy.