Background: Group B streptococcus (GBS) is gram-positive coccus which is a normal flora ofrnthe intestines, vagina or rectum and around 25% of healthy women carry this bacteria withoutrnshowing any symptom. Bacteraemia, endometritis, amnionitis and urinary tract infection arernmajor cause of bacterial infections caused by GBS in pregnant women in perinatal time, and inrnneonates it causes sepsis and meningitis. New born get infected through intra-amniotic route orrnat time of delivery. rnObjective: To determine GBS prevalence in pregnant women and outcome of neonates inrnZewditu Memorial Hospital Addis Ababa rnMethods: A cross-sectional study design conducted at Zewditu hospital in city of Addis Ababa,rnEthiopia from January 2019 to June 2019. A total of 192 pregnant women participated onrnisolation of group B S.agalactiae. For GBS isolation from vaginal swabs and antimicrobialrnsusceptibility pattern standard operating procedures were followed. Culture, gram stain, catalasernreaction and CAMP test, and testing for their susceptibility to antimicrobial agents werernperformed. All collected data was organized and tabulated using SPSS version 20, MultiplernLogistic regression analysis was used to see the association between variables finally the resultsrnwas summarized by using tables. rnResults: The age was between 18 to 38 years with a mean of 28.34 Â± 3.66 years. From 192rnpregnant mothers 30(15.6%) were GBS culture positive. The highest participation 161(83.9%)rnrecorded between the ages of 25-35 years. From all participants the highest 70(36.4%) werernhouse wives. GBS colonization showed a statistically significant association with primary levelrnof maternal education and newborn birth weight. High susceptible of GBS isolate was seen tornpenicillin G & chloramphenicol (93.3%) for each, ampicillin, and ceftriaxone (90%) each,rnfollowing vancomycin (80%) and erythromycin (70%). Relatively, GBS showed high resistancernto tetracycline (86.7 %), ciprofloxacin (46.7 %) and clindamycin (33.3%). In this study thernbabies born to women with GBS colonization had statically significant association with clinicalrnsepsis and low birth weight. rnConclusion: In this study, the overall prevalence of GBS colonization was 15.6%. Primaryrneducational level and low birth weight was statistically significant with GBS colonization. Thisrnstudy used to give attention during management of pregnant women by making GBS culture asrnone of routine diagnosis during ANC follow up and to prevent newborn infection by earlyrndetection.