Diabetes mellitus (DM) is an increasingly prevalent metabolic disorder and poses a growing public health concern in Tanzania, particularly in rapidly urbanizing areas like Morogoro. This cross-sectional study investigated the prevalence of diabetes and its associated risk factors among 129 outpatients at Morogoro Regional Referral Hospital. Diabetes was diagnosed based on random blood glucose levels ≥11.1 mmol/L and fasting plasma glucose ≥7.0 mmol/L. Participants provided socio-demographic and lifestyle information through structured questionnaires, and Body Mass Index (BMI) was calculated. The overall prevalence of undiagnosed diabetes was found to be 10.08%, with a higher proportion of cases among women (69%) than men (31%). Risk factors significantly associated with diabetes included being overweight or obese, older age, and alcohol consumption. These findings suggest that the prevalence of diabetes in this population exceeds national estimates and highlight the need for regular screening and targeted preventive strategies to address modifiable risk factors such as lifestyle and dietary habits. Strengthening early detection and intervention efforts is essential to reducing the burden of diabetes and its complications in Tanzania.