Introduction: Asymptomatic bacteriuria is the significant presence of bacteria in urine of an individual without symptoms. The aim of the study is to determine the prevalence of asymptomaticbacteriuria in pregnant women. Methods: This study was a prospective study conducted in the department of Obstetrics and Gynaecology at B. P. Koirala Institute of Health Sciences. The duration of the study was six monthsfrom January to June 2012. A total of 600 pregnant women were enrolled. All women were clinically identified to have no signs and symptoms of UTI. Clean catch midstream urine sample was collectedfrom each patient into a sterile vial. The urine samples were examined for microscopic and culture sensitivity test. Results: Out of 600 pregnant women, 52 were positive for significant bacteriuria with a prevalence rate of 8.7%. There was a significant difference in prevalence of asymptomatic bacteriuria withrespect to trimester (p=0.005). Age did not show any significant difference in the prevalence of asymptomatic bacteriuria (p=0.807). There was not any significant difference in the prevalence ofasymptomatic bacteriuria with respect to parity (p=0.864) and booking status (p=0.397). Escherichia coli (35%), Acinetobacter species (15%), Enterococcus species (12%) and Klebsiella pneumoniae (10%)were the common isolates. Most of the isolates were sensitive either to Nitrofurantoin, Norfloxacin or Amikacin. Conclusions: Asymptomatic bacteriuria is common in pregnancy. Urine culture sensitivity should be carried out routinely on all pregnant patients in order to prevent the dangerous complicationsassociated with it. Keywords: asymptomatic bacteriuria in pregnancy; urine culture and sensitivity.