SUMMARY Background Asymptomatic bacteriuria in pregnancy is the major risk factor for symptomatic urinary tract infection during pregnancy. Screening and identification of bacteriuria during pregnancy have been recommended. Setting Antenatal clinic of the University College Hospital, Ibadan. Objectives The specific objectives of the study were to determine the prevalence of asymptomatic bacteriuria at the University College Hospital, Ibadan, to determine the bacterial isolates responsible for the asymptomatic bacteriuria and their antibiotic sensitivity pattern and to evaluate the diagnostic accuracy of dipstick test for nitrite and leucocyte esterase in comparison to laboratory culture Methodology The study was descriptive and cross sectional in design. All consecutive patients presenting for the first antenatal visit between 1st of April and 31st of May 2006, who met the inclusion criteria and who consented to participate in the study were recruited. Two hundred and five patients participated in the study. Urine samples were obtained from the participants after adequate counselling and education. Each sample was subjected to two tests; reagent dipstick test for nitrite and leucocyte esterase and routine laboratory culture. Participants were requested to come back to the hospital one week after sample collection for review with culture result. Participants whose urine culture reports were positive for bacteriuria were treated according to the antibiotic sensitivity pattern. They were also followed up after completion of antibiotic therapy with repeated urine culture to ensure clearance of bacteriuria. Results The prevalence of asymptomatic bacteriuria among our obstetric patients was 10.7%. The prevalence was higher among women aged between 16-20 years (33.3%) and 31-35 years (12.1%); those with no formal education (33.3%); Christian women (12.7% compared to 4.7% among Muslims) and women with genotypes AS and AC (16.4% and 16.7% respectively). Prevalence was also higher among para 2 and in 2nd and 3rd trimesters. However the influence of these demographic parameters, parity and gestational age on prevalence rate of asymptomatic bacteriuria were not statistically significant. The bacterial pathogens causing asymptomatic bacteriuria were predominantly coliforms (Klebsiella and E. coli) accounting for 45.5% and staphylococcus saprophyticus (27.3%). Only gentamycin, nitrofurantoin and ofloxacin demonstrated high efficacy against these uropathogens (Antibiotic sensitivity rate between 72.7%-81.8%). Combined use of leucocyte esterase and nitrite strip demonstrated a reasonable level of accuracy in detecting asymptomatic bacteriuria with sensitivity, specificity and negative predictive values of 50%, 92.9% and 93.9% respectively. Conclusion Prevalence of asymptomatic bacteriuria in this centre is relatively high and this underscores the need for routine screening of our pregnant women for this condition. Leucocyte esterase–nitrite dipstick demonstrates fair sensitivity and high specificity and may be more cost-effective for screening for asymptomatic bacteriuria in our low resource setting.