The consequences of a prior human herpesvirus-8 (HHV-8) infection in kidney-transplant recipients are still partially unknown. The aim of this monocentric study was to determine the prevalence of HHV-8-seropositive patients at the time of transplantation and to identify the main clinical events of these HHV-8+ recipients. From January 1, 1990 to December 31, 1996, antibodies to HHV-8 latent nuclear antigen were detected by indirect immunofluorescent method in serum samples collected just before kidney transplantation from 400 consecutive patients. Conventional double or triple immunosuppressive treatment was prescribed. For the group of HHV-8+ recipients, data including death rate, graft survival, and occurrence of Kaposi's sarcoma (KS) were retrospectively collected until December 31, 1998. Cofactors associated with KS were studied in univariate and multivariate analyses using a Cox model. Thirty-two patients (8%) had antibodies to HHV-8 in their sera at the time of transplantation. Among these 32, 3 years after transplantation, graft survival was 72%, and KS prevalence was 28% (KS incidence: 8.2/yr/100 HHV-8+ recipients). Multivariate analysis identified bacterial and/or Pneumocystis carinii infection (odds ratio: 8.6; P=0.019) and female gender (odds ratio: 5.34; P=0.047) as factors associated with KS. No KS was observed in patients without anti-HHV-8 antibodies at the time of transplantation. The low graft survival and the high prevalence of KS within the studied population of HHV-8+ transplant recipients are strong arguments for systematic screening of HHV-8 serologic features before transplantation, especially in patients of African origin. HHV-8+ transplant recipients should be closely monitored to severe infections.