Objectives: Group B Streptococcus (GBS) has been recognized as the leading cause of serious neonatal infections through mother-fetal vertical transmission in the west, however, in India, its spectrum is largely under estimated. The present study was carried out to find the incidence of rectovaginal carriage of GBS in parturient women, association with risk factors in mother and to study the neonatal outcome. Materials and methods:A one year cross-sectional prospective study was carried out in 905 parturient women admitted at a tertiary care center meeting the selection criteria over a period of one year from June 2007 to May 2008. The inclusion criteria were all pregnant women admitted to the labor room after 35 ± 1 week of gestation. Rectal and vaginal swabs were taken and cultured on selective Todd-Hewitt broth medium followed by sub culture on blood agar and confirmation by Latex agglutination test from all the women meeting the inclusion criteria. The outcomes measured were the incidence, antenatal risk factors in mother and the neonatal outcome. Analysis was done using paired 't' test, chi-square test and a p-value of <0.05 was taken as statistically significant. Results:Incidence of group B Streptococcus (GBS) was 12.15% and detection rate was increased by 4.6% with the inclusion of rectal swabs for culture. GBS carriage was significantly increased with preterm birth (OR 8.3, 95% CI,1.1-15.5), premature rupture of membranes (OR 7.5, 95% CI, 1.1-13.4), prolonged duration of ruptured membranes more than 10 hours (OR 21, 95% CI,15.2-34.2) and intrapartum temperature more than 38°C(OR 3.1, 95% CI, 0.43-6.66). Birth weight less than 2.5 kg and neonatal intensive care admissions were significantly more (35.45%) in infants of GBS positive women. Conclusion:GBS colonization was more frequent in women with risk factors. GBS pick up rate was increased by the inclusion of both rectal and vaginal swabs.