A newborn male born was admitted on the second day of life to the paediatric ward of the Provincial Observation and Infectious Hospital suspected of vertical human immunodeficiency virus (HIV) infection. In the mother's study, on the day of delivery, HIV markers were detected, which were confirmed on the following day by Western blotting. In the first day of life, the child was vaccinated against tuberculosis and hepatitis B. Before entering the infectious hospital ward, the newborn was breastfed several times until the second day of life. Laboratory tests showed elevated total bilirubin (6.82 mg/dl) with unincorporated bilirubin predominance (6.4 mg/dl). The viraemia of HIV RNA, which was undetectable, was evaluated by PCR. In accordance with the recommendations of the Polish AIDS Scientific Society, the newborn used triple antiretroviral therapy (ARV): zidovudine (ZDV), lamivudine (3TC), and nevirapine (NVP) in the following doses: ZDV – 2 × 14 mg for each day, 3TC – 2 × 7 mg for each day, and NVP – 2 × 7 mg. Treatment with ZDV and 3TC was continued for four weeks, and NVP for the first two weeks of therapy. In the presented case, during the three- and six-month follow-up visits HIV viral RNA was undetectable, the CD4+ cell amount was normal, and there were no deviations in psychomotor development, indicating that the prophylaxis of vertical HIV was effective.