Respiratory distress (RD) within the first days of life is a common sign of early-onset bacterial infection. The bacterial etiology of early-onset neonatal infection varies from one population to another. Gram-positive organisms such as GBS are an infrequent cause of neonatal infection in some tropical countries. In Brazil, there role of GBS in neonatal infection is unknown. The aim of this study was to determine the frequency of bacterial infection in Brazilian newborns with RD considering the relative distribution of each pathogen. All of 261 consecutively admitted newborns who had RD within 96 hours of life (excluding aspiration syndromes, transient tachypnea, cardiac disease or congenital anomalies) were evaluated. Before the use of antibiotics, a blood culture, a urine culture, a latex test to detect GBS antigen in concentrated urine samples and leukocyte counts were done. Infants with positive blood cultures for pathogenic non-contaminant organisms were considered to have a confirmed infection. A true infection with S. epidermidis was considered in the presence of suggestive clinical and laboratory evidence. Infants with negative blood culture and positive GBS antigen urine tests with negative urine culture were considered to have presumed infection by GBS if clinical and laboratory signs were present. The newborns studied had a median gestational age of 32 weeks and a median birth weight of 1400 g. Screening of pregnant women for GBS colonization was not done. Only 3 of the 37 (8.1%) mothers of these newborns received antibiotics prior to delivery. Overall, there were 37/261 (14.2%) newborns with bacterial infection. The majority (78.4%) of neonatal infections were caused by Gram-positive organisms (29/37). The remaining 8 (21.6%) newborns were infected by Gram-negative organisms. GBS was the single most frequently detected pathogen among infected infants (35%) followed by S.epidermidis (13.5%), E. coli (10.8%), S. viridans (10.8%), other streptococci (10.8%), S. aureus (8.1%),H. influenzae (5.4%) and P. mirabilis (5.4%). Taking into account that GBS was detected in 5% (13/261) of all newborns with RD and that this organism has emerged as the major pathogen detected in this population, the implementation of regimens for prevention of GBS disease is strongly warranted.