Background Globally, diabetes affects 537 million individuals aged 20-79, significantly undermining their quality of life and economic stability, with the greatest impact in low- and middle-income countries. This study aims to deepen understanding of the diabetes burden in Ga Mashie, an urban-poor area in Accra, Ghana. Methods We conducted a cluster survey of adults over 25 years in 80 enumeration areas within Ga Mashie, targeting 959 eligible households based on the 2021 census. Household-level data included household membership and structure, water and sanitation, cooking infrastructure, and asset ownership. Individual-level data encompassed demographics, lifestyle behaviours, and biometric measurements. Diabetes was identified through random blood glucose levels ≥11.1 mmol/L or a prior diagnosis, with obesity defined as a body mass index >30 kg/m2 and central obesity as a waist circumference-to-height ratio >0.5. We derived weighted prevalence estimates and compared these estimates by age, sex, and wealth, using unadjusted odds-ratios (OR). Results The survey, achieving a 67% response rate, covered 854 individuals from 644 households. It unveiled a notable prevalence of non-communicable disease risk factors: 47.2% for alcohol consumption (95% CI: 43.7-50.8), 73.3% for insufficient physical activity (95% CI: 69.1-77.1), 28.9% for unhealthy snack consumption (95% CI: 24.5-33.7), 35.1% for obesity (95% CI: 31.3-39.1), and 74.5% for central obesity (95% CI: 70.8-77.9). Diabetes affected 8.2% of the population aged ≥25 (95% CI: 6.4-10.5), with disparities evident across age, wealth, and sex (2.66 greater odds in females for diabetes [95% CI: 1.38-5.12]). Conclusion Diabetes and its risk factors are highly prevalent in Ga Mashie, with significant demographic disparities underscoring the need for targeted interventions. The study highlights the critical challenge diabetes poses in urban-poor contexts, emphasizing the necessity for tailored health initiatives to mitigate this burden.