Apelin was proved to attenuate cardiac interstitial fibrosis. However, the association between apelin level and myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) is still unclear. This study aims to determine whether apelin is associated with myocardial fibrosis in HCM and investigate the predictive values of apelin for myocardial fibrosis in HCM. One hundred sixteen patients with HCM were enrolled in this study. Plasma apelin-13 and high-sensitivity cardiac troponin I (cTNI) were measured. The cardiac systolic and diastolic functions were evaluated by echocardiography, and the presence and extent of cardiac fibrosis were assessed by cardiac magnetic resonance. All statistical data were analyzed by SPSS version 21.0. The percentage of late gadolinium enhancement (LGE) was negatively correlated with apelin and positively correlated with cTNI, maximum wall thickness (MWT), and left ventricular mass index in the overall patients with HCM and LGE. Apelin, cTNI, MWT, and left ventricular ejection fraction were independent predictors of the presence of LGE. The cutoff values of apelin. cTNI, and MWT were 1.24 pg/mL, 0.031 ng/mL, and 19 mm, respectively, for the prediction of LGE. The combined measurements of MWT >= 19 mm and/or apelin <= 1.24 pg/mL, as well as the combined measurements of MWT >= 19 mm and/or cTNI >= 0.031 ng/mL. obtained higher specificity and higher sensitivity, thus, indicating the presence of LGE. Plasma apelin and cTNI are independent predictors of myocardial fibrosis. The combined measurements of serum apelin and MWT, as well as cTNI and MWT, showed higher predictive values for predicting myocardial fibrosis in patients with HCM.