Pregnant women coinfected with the human immunodeficiency virus (HIV) and human gammaherpesvirus 8 (HHV-8) are at higher risk of Kaposi’s sarcoma development, increased viral load, and vertical transmission of these viruses. A total of 131 pregnant women infected with HIV were examined for antibodies against HHV-8 latency-associated nuclear antigen (LANA) and lytic antigens using immunofluorescence assays. The presence of HHV-8 DNA was confirmed using real-time polymerase chain reaction (qPCR) and nested PCR. Overall, 0.8% (1/131) of the patients contained antibodies to HHV-8 LANA and lytic antigens, and no HHV-8 DNA was detected. This study, including a small population of HIV-infected pregnant women in Brazil, indicates a low prevalence of HHV-8 seropositivity and absence of active infection in this group. However, a potential role of HHV-8 in the increased transmission and pathogenic activity of HIV in pregnant women is suggested. Attention should be given to the emergence of HHV-8 infection in this population group in order to avoid comorbidities and transmission of HIV.