In this study, we have sought to verify the prevalence ofhuman herpesviruses 6 and 7 (HHV-6, HHV-7) in the saliva of renal transplanted patients from Rio de Janeiro State, Brazil, and compare results with those of healthy subjects, since Roseolovirus DNA detection in body fluids from transplanted patients has been associated with often misdiagnosed chronic symptoms, organ rejection and even death. The studied group was composed by 120 individuals: 60 were renal transplanted patients and 60 were healthy subjects attending the Hospital Universitário Pedro Ernesto, for odontological follow-up. Saliva specimens were submitted to a multiplex nested polymerase chain reaction (PCR) to detect the presence of HHV-6A, HHV-6B and HHV-7. The total Roseolovirus DNA prevalence was 56.7% for transplanted patients and 23.3% for healthy individuals (p<0.001). For immunossupressed patients, the PCR detected a HHV-6A prevalence of 16.7% in transplanted, HHV-6B in 26.6% and HHV-7 DNA was revealed in 13.3% of the studied cases. In healthy subjects, HHV-6A was found in 5% of the samples, HHV-6B in 6.7% and HHV-7 in 11.7%. Multiple infections were observed in 12/60 (20%) individuals. No co-infection was demonstrated for healthy subjects, reinforcing the idea that imunnossuppression can favor reactivation and possibly transactivation among herpesviruses (P<0.001). Statistically significant differences were recorded for HHV6A and B infections in transplanted patients, when compared with healthy individuals (p<0.05). No statistically significant differences were observed regarding HHV-7 infection. Clinical symptoms and laboratorial findings were not specifically associated with patients shedding any of the studied viruses. Our results showed relevant differences in Roseolovirus prevalence among the two studied groups, suggesting a potential role for those viruses in disturbing host homeostasys that can compromise life quality. Although PCR methodology proved to be a useful tool for Roseolovirus detection, the standardization of samples and procedures is necessary to evaluate possible a pathogenic behavior among different agents in order to analyze their role in the post-transplant scenario.