Objective.To compare the diagnostic performance of urine microscopy, leucocyte esterase and nitrite dipstick tests and various combinations of these as screening tests for asymptomatic bacteriuria in pregnancy. Methods. Pregnant women (N=800) attending an antenatal clinic were recruited at their first visit. Urine microscopy, culture and dipstick testing were performed on a random clean-catch midstream urine sample. A count of >10 5 colony-forming units of a single organism per millilitre of urine was taken as significant. Dipstick results were read as positive according to the manufacturer's instructions. Results. A total of 800 eligible women were screened. The prevalence of asymptomatic bacteriuria as diagnosed by urine culture was 5.0% (n=40). Escherichia coli was the most prevalent uropathogen isolated by culture (60.0%). Neither urine microscopy nor the leucocyte test was found to be sufficiently sensitive to be used as a single screening test for asymptomatic bacteriuria in pregnant patients. The nitrite test alone had a sensitivity of 82.5% and a specificity of 99.9%. Combined dipstick testing had an improved sensitivity of 87.3% and a specificity of 96.2%. Addition of urine microscopy to combined dipstick testing increased the sensitivity to 95.0%, and the specificity became 92.4%. Conclusion. Combined dipstick testing is a useful screening test for asymptomatic bacteriuria in pregnancy. Addition of urine microscopy to combined dipstick testing further improves its diagnostic performance.