[Abstract] Objective：To investigate the correlation between frailty status and disease severity in elderly patients with coronary artery syndrome (CAS) and analyze risk factors in this population. Methods：This analytical cross-sectional study included 187 elderly patients diagnosed with CAS at the First Affiliated Hospital of Nanjing Medical University from September 2023 to September 2024, who underwent coronary angiography and intervention. Participants were categorized into non-frail, pre-frail, and frail groups using the FRAIL Scale. Coronary lesion severity was assessed using the Gensini score, and cardiac structure/function was evaluated via echocardiography. A Gensini score >43 (defined by the tertile method) was classified as high. Risk factors were screened using univariate analysis and further analyzed via multivariate logistic regression. Restricted cubic splines were applied to test nonlinear relationships. Results : The cohort comprised 74 non-frailty, 72 pre-frailty, and 41 frailty cases. Pre-frailty and frailty groups had higher mean ages and increased proportions of NYHA class III cardiac function (P<0.05). Atrial fibrillation and low glomerular filtration rates were more prevalent in frailty and pre-frailty groups compared to non-frailty (P<0.05). High Gensini scores occurred more frequently in frailty (36.6%) and pre-frailty (33.3%) groups than in non-frailty (20.3%), though differences were not statistically significant (P>0.05). Left atrial diameter progressively increased across non-frailty (36 mm), pre-frailty (38 mm), and frailty (40 mm) groups (P<0.05). Left ventricular end-diastolic diameter was larger in pre-frailty (50 mm) versus non-frailty (47.5 mm, P<0.05). Segmental wall motion abnormalities were higher in frailty (24.4%) and pre-frailty (38.9%) groups than in non-frailty (17.6%, P<0.05). Logistic regression identified hypertension, diabetes, fasting glucose, and segmental wall motion abnormalities as positively correlated with high Gensini scores (all P<0.05), while BMI showed a negative correlation (OR=0.872, 95% CI: 0.775–0.980, P=0.021). Spearman analysis revealed a weak negative correlation between BMI and Gensini scores (R=-0.161, P=0.028). Restricted cubic splines indicated no significant nonlinear relationships between BMI and Gensini scores overall or within frailty subgroups (P>0.05). Conclusion :Frailty status was not significantly associated with coronary lesion severity in elderly patients with coronary syndrome. However, frailty and pre-frailty were linked to increased cardiac structural abnormalities and impaired contractile function.