The prevalence of coronary artery disease (CAD) is growing in the young population. We aimed to investigate the association between serum uric acid (SUA) levels and cardiovascular involvement in individuals under 45 years old diagnosed with early-onset CAD (EOCAD). Seven hundred eighty-six EOCAD patients were recruited and stratified into four groups by SUA levels. General information, serum indicators, and results of coronary angiography and echocardiography were recorded. The associations between SUA levels were explored by univariate and multivariate logistic regressions. With the increasing of SUA levels, the prevalence of hypertension and hyperlipidemia, triple branches involved, heart failure, and cardiac enlargement of left ventricle (LV), left atrium (LA), and right ventricle (RV) were significantly higher (all P < 0.05). The fourth group (SUA >8 mg/dl) had the highest proportions than other groups (all P < 0.05). After controlling potential confounders, multiple logistic regression analysis showed that odds ratios of SUA >8 mg/dl were 2.345 for triple branches involved (95 % confidence interval (CI) 1.335-4.119), 4.168 for heart failure (95 % CI 1.599-10.862), and 4.122 for LV enlargement (95 % CI 1.874-9.065) (P < 0.05). SUA >8 mg/dl was independently associated with triple branches involvement, heart failure and LV enlargement in Chinese EOCAD patients. Higher SUA level might play an important role in cardiac dysfunction and severity of EOCAD.