ABSTRACT Background:Coronary artery calcification (CAC) is a reliable marker of atherosclerosis and a strong predictor of coronary artery disease and major cardiovascular events. In Ethiopia, where dedicated cardiac CT is limited, local evidence on CAC prevalence and determinants is lacking. Routine non-gated chest CT provides an opportunity to detect incidental CAC. This study aimed to determine theprevalence and associated factors of CAC among adults undergoing routine chest CT at TibebeGhion Specialized Hospital. Objective: To assess the magnitude of coronary artery calcification and associated factors among adult patients who underwent routine non-gated chest computed tomography at TibebeGhion Specialized Hospital between November 1, 2024, and October 31, 2025. Methods:An institution-based cross-sectional study was conducted among 302 adults aged ≥40 years who underwent non-gated chest CT between November 1, 2024, and October 31, 2025, GC at TGSH. Systematic random sampling was used to select participants. Data were collected using a structured checklist and analyzed using SPSS version 27.A binary logistic regression analyses were performed to identify factors associated with CAC. Adjusted odds ratios with 95% confidence intervals were calculated, and p-values <0.05 were considered statistically significant. Results:The prevalence of visually detectable CAC was 15.2% (95% CI: 10.9%-19.1%). Most cases were mild (11.3%), followed by moderate (3.3%) and severe (0.7%). Increasing age (AOR = 1.071; 95% CI: 1.029–1.116), hypertension (AOR = 3.093; 95% CI: 1.230–7.775), diabetes mellitus (AOR = 4.059; 95% CI: 1.057–15.582), and thoracic aortic calcification (AOR = 2.570; 95% CI: 1.085–6.083) were significantly associated with CAC. CAC was documented in only 2.2% of formal radiology reports. Conclusion: This study foundCAC is relatively common but markedly underreported on routine Chest CT Scan. It is significantly associated with aging, hypertension, diabetes and thoracic aortic calcification. Routine visual assessment and systematic documentation could enhance opportunistic cardiovascular risk stratification and support cost-effective prevention strategies in resource-limited settings.