Seven autopsies performed on immunosuppressed bone marrow transplant recipients who died with documented herpes virus infection were reviewed. The kidneys were studied by light and electron microscopy and revealed no pathological findings, specifically no glomerulopathy or tubular interstitital nephritis. Seven renal biopsies performed on kidney transplant recipients in whom a diagnosis of cytomegalovirus glomerulopathy was entertained were also studied. These patients exhibited clinical parameters suggestive of cytomegalovirus infection. Three patients had subsequent nephrectomies and two showed severe acute vascular rejection. The one kidney without demonstrable acute vascular rejection was negative for cytomegalovirus on culture. Three additional patients improved or stabilized their renal function under therapy for rejection. Light, electron microscopic and immunofluorescent studies, although confirmatory of endothelial cell damage, did not substantiate active cytomegalovirus renal infection in these patients. An additional group of fifteen children with disseminated cytomegalovirus infection revealed no evidence of glomerulopathy. Finally, two kidney transplant recipients with proven cytomegalovirus infection (one with associated tubular interstitial nephritis) also showed no glomerular alterations. It is the author's opinion that the entity that has been considered as cytomegalovirus glomerulopathy probably represents rejection, either a peculiar anti-endothelial type of rejection or a protracted, early, or partially resolved acute vascular rejection without residual or identifiable acute vascular rejection changes in the tissue sampled.