Aims: Asymptomatic bacteriuria (ASB) has been considered as a complication in diabetic women. The reported data on the prevalence and various risk factors for ASB appear to be conflicting. Consequently, we investigated the prevalence and major risk factors of ASB in women with Type 2 diabetes mellitus. Methods: A total of 411 non-pregnant women (aged 59.6 +/- 10.8 years) with Type 2 diabetes, and 160 women without diabetes (aged 53.3 +/- 15.1 years) assigned as controls, attending an outpatient endocrine clinic in a university-affiliated teaching hospital, were included. All participating women were interviewed and screened for the presence of ASB. In all participants, fasting blood glucose, HbA(1c) and renal function were measured. Complications of diabetes were also assessed. Results: Of the 411 diabetic women, 25 (6.1%) had ASB, compared with four of 160 (2.5%) in control women (P = 0.07). Independent risk factors for the presence of ASB were albuminuria > 150 mg/24 h [odds ratio (OR) 4.96 (95% CI 1.64-15.0, P = 0.005)] and serum creatinine [OR 3.5 (95% CI 1.4-8.8, P = 0.008)]. No significant association was evident with age, BMI, duration of disease, glycaemic control assessed by HbA(1c) or chronic complications of diabetes, namely macrovascular disease, neuropathy and retinopathy. Conclusions: Women with Type 2 diabetes are not at higher risk of developing ASB than non-diabetic women. Independent and significant risk factors for ASB are macroalbuminuria and serum creatinine. The low prevalence of ASB found in this study may be as a result of the ethnic origin of these women and the circumcised state of their partners.