Background: Streptococcus agalactiae (Group B Streptococcus, GBS) is one of the causes of maternal and neonatal morbidity and mortality. It is associated with severe infections including pneumonia, septicaemia, and meningitis in new-borns. GBS are being reported with increased resistance to the commonly used antibiotics. The colonization rate, associated factors and antimicrobial susceptibility (AST) profile of GBS among pregnant women in Eastern Ethiopia, especially in the present study area, is less studied