Mother-to-child transmission of human immunodeficiency virus (HIV) can be prevented by prenatal, perinatal and postnatal interventions. Although the incidence of HIV infection in Turkey is low, the number of cases are increasing in years. The aim of this study was to evaluate the characteristics of infants with HIV-positive mothers followed in a pediatric HIV center in Istanbul, Turkey and to describe the vertical transmission of HIV infection among the cases. Clinical and laboratory features of HIV-infected mothers and their exposed infants, followed in our department between June 2007 and February 2015 were retrieved from medical records retrospectively. The data about HIV infection and pregnancy course were confirmed with medical records when possible otherwise based on mothers' self-reports. Clinical and laboratory data about the birth and after birth of the babies in the other centers were obtained from the related centers. A total of 32 HIV-exposed infants (18 female, 14 male) were followed in eight years. HIV infection could be diagnosed in 15 (46.9%) mothers before pregnancy, in 10 (31.3%) during pregnancy and in seven (21.8%) during delivery. Nine of the mothers (28.1%) did not receive antiretroviral therapy during pregnancy. The median age for the patients at the admission were 13.5 days in which the earliest was a day and the latest was 420 (14 months) days. Three of the infants were fed with breast milk. Four infants (12.5%) did not receive antiretroviral prophylaxis. Cotrimoxazol prophylaxis were given approximately to 60% (n=19) of the infants starting from 4-6 weeks. HIV viral load could be tested within the first 48 hours among 20 infants and except one, all was found as negative. A total of two infants (6.2%) were infected with HIV and their initial viral loads were 89.500 and 87.500 copies/ml, respectively. One of the infant was delivered vaginally and his mother's HIV status was detected during delivery. The mother of other infected infant was diagnosed only three weeks before birth and delivered with cesarean section. Both mothers had high viral loads just before delivery (> 102.000 and 67.000 copies/ml, respectively). One of the infants infected with HIV died in the 4th month due to pulmonary infection and sepsis. This study reveals a high rate of perinatally transmitted HIV infection and mortality. The limited number of cases involved in this one-center study should be taken into account while interpreting this result. All pediatric HIV centers in Turkey should work as partners for more precise national results. Nevertheless, our results draw attention to the lack of prenatal follow-up evaluation in women. In particular, the prompt diagnosis of HIV infection in pregnancy should be provided or not to be missed and follow-up of pregnant women with HIV should be carried out by specialist centers.