Study was conducted to understand contemporary levels of resistance to commonly used antimicrobial agents for aerobic bacteria obtained from urine samples of pregnant (3000) and non– pregnant women (300)in treatment of Asymptomaticbacteriuria, in Nair Hospital, Mumbai. Microscopic examination of urine and identification of isolates & its susceptibility to antibiotics were carried out by standard methods.In both groups,E.coli strains were predominant, followed by Klebsiellaspp. E.coli (100%), Pseudomonas aeruginosa (83.3%), Proteus mirabilis strains (100%) were sensitive to Piperacillin + Tazobactum .Klebsiellapneumoniae (70.2%), Staphylococcus epidermidis (93.8%) and Enterococcus faecalis (93.4%) strains showed sensitivity to Nitrofurantoin, while Klebsiellaoxytoca  (80%) strains to Amikacin, Acinetobacterbaumanii (81.9%) strains to Ceftriaxone and  Cefotaxime and Staphylococcus aureus(100%) strains to Vancomycin. Antibiotic susceptibility tests are intended to be guide for clinician, not a guarantee that an antimicrobial agent will be effective in therapy