Introduction: This paper is a prospective study that included mother-newborn pairs that were performed the screening for GBS porting. The goal of the study: Setting the incidence of maternal and neonatal colonization with group B Streptococcus, identifying risk factors for perinatal infection with group B Streptococcus and early detection of infection in order to reduce neonatal morbidity and mortality. Materials and Methods: This study was conducted within PMSI MCH no.1, comprising mother-newborn pairs. The sample size of the study was 549 women in 2013 and 597 in 2014. For clinical and laboratory correlations were studied 29 children, 13 of them born in 2013 and 16 in 2014. The screening for pregnant women porting and postpartum period for GBS was conducted by chromoimmunological rapid test and by culture. The material was processed statistically through mathematical and variation strings. Results: Analyzing data of investigated mothers it was observed that the percentage of colonization with group B Streptococcus rose on account of enrollment in study and mothers with term of pregnancy less than 34 weeks of gestation. A total of 1146 examined pregnant who have risk factors during pregnancy were detected in group B Streptococcus positive 5,9% (68) women. Intrapartum antibiotic prophylaxis has been applied in 8.57% cases spite that women have risk factors that would have required intrapartum antibiotic prophylaxis. When analyzing neonatal cases of GBS positive mothers, it was determined a colonization in newborns who basically stay the same in the years 2013 and 2014, from 15,54% to 16.38%. From suggestive clinical signs of infection for newborn were recorded mainly cutaneous signs of growth in 2014 (50%) compared with 2013 (38,09%), the Cardiovascular – 23,80% in 2013 compared with 28,57% in 2014 and neurological 22,85% in 2014, compared with 19,04% in 2013. The neonatal sepsis in newborns colonized with GBS occurred in 13 cases (5%) in 2013 and in 2014 - in 16 children (11%). The most virulent combination was found to be E.coli GBS and E. coli Str. hominis, which in all cases was manifested with clinical infections, the other combinations of bacterial agents in the present study were less incriminated in achieving infection in the newborn. Conclusions: The study demonstrated that severe forms of group B Streptococcus infection are more common than lighter ones, which can be explained by the increasing number of mothers colonized or by strains more invasive of GBS. Knowing the risk factors and the onset clinical signs of infection contributes to early detection of infection and intrapartum antibiotic prevention administered at least 4 hours before birth is the intervention that would allow a decreased risk of neonatal infection.