Background: Group B streptococci are known to cause a wide variety of infections in adults, but clinical interest in these bacteria mainly relates to their ability to cause serious neonatal illness especially meningitis and sepsis. Aim: The aim of the study is to determine the prevalence of vaginal group B streptococcus (GBS) colonization and the associated maternal and neonatal outcome among pregnant women at Olabisi Onabanjo University Teaching Hospital Sagamu. Methodology: This was a cross-sectional descriptive study of pregnant women presenting in the antenatal clinic of the department of obstetrics and gynaecology of Olabisi Onabanjo university teaching hospital sagamu between the gestational age of 36-40weeks. Consenting women were recruited for the study until the estimated sample size of 184 was reached. Lower vaginal and rectal swab specimen was collected and transported to the Medical Microbiology Laboratory of O.O.U.T.H, Sagamu. These were examined using standard bacteriological procedures. Babies of GBS positive mothers were observed and screened for evidence of infection by the organism. The demographic characteristics of the participants as well as data on potential predictors of group B streptococcus was recorded. Data analysis was done using IBM-SPSS statistics for windows version 21.0 (IBM Corp., Armonk, NY, USA). Main Outcome: The main outcome measured were the presence of GBS infection among pregnant women, the associated socio-demographic and obstetric factors. Others were neonatal outcome which includes neonatal sepsis, meningitis, pneumonia and also antibiotics sensitivity pattern.