Type 2 diabetes mellitus (T2DM) prevalence is increasing rapidly around the world. This cross-sectional study was conducted to assess the prevalence and awareness of type 2 diabetes mellitus in Mwanza city, Tanzania. A multistage random sampling technique was used to obtain representative subjects. Information about causes and risk factors were collected using structured questionnaire. In addition, community random blood glucose testing was employed to identify those at risk. Subjects with ≥ 200 mg/dl on the following day were subjected to fasting blood glucose testing and they were confirmed to have T2DM if they had blood glucose level of ≥ 126 mg/ dl. In each subject, height, weight, waist and hip circumferences and total fat and fat free mass were measured using standard procedures. A total of 640 participants were included in this study, 55% were females and 45% were males. Mean age of the respondent was 43.84 ± 10.80 years. Most (46.4%) respondents were in the age group 30-40 years. Mean age for females was 44.0 ± 10.31 years while for males was 43.6 ± 11.3 years (Table 1). Overall prevalence of T2DM was 11.9%, (n = 76). Prevalence was high in females (7.2%; n = 46) than in males (4.7%; n = 30). The age between 41-50 years had the highest prevalence of T2DM 28.6% followed by 51-60 years age group (17.2%). Significant independent associations were found for age (OR 3.88, 95% CI: 2.16-6.95) positive first degree relative with T2DM (OR 1.34; 95% C: 1.10-1.64) alcohol intake (OR 1.23; 95% CI: 1.02-1.48,) smoking (OR 3.86; 95% CI: 2.57-5.78) and hypertension (OR 0.096; 95% CI: 1.954-18.251). Only 49.2 (n = 315) of the respondents knew about the causes and symptoms of T2DM. Public education on T2DM should be emphasized and routine measurement of blood glucose levels is recommended among adults.