Hypertrophic cardiomyopathy is a primary cardiac disease characterized by left ventricular hypertrophy, myocyte hypertrophy and irregularities and interstitial fibrosis in the absence of any cardiac or systemic diseases and may lead to sudden cardiac death (SCD). Galectin-3 is a β-galactoside-binding lectin that has been associated with cardiac fibrosis and inflammation. In this study, we aimed to investigate the relationship between serum galectin-3 levels and the criteria for 5-year sudden death risk, recently defined in the European Society of Cardiology guidelines (2014), in patients with hypertrophic cardiomyopathy.A total of 52 hypertrophic cardiomyopathy patients were enrolled in the study. Patients were questioned for sudden death risk predictors as outlined in the 2014 European Society of Cardiology guideline. A standardized clinical evaluation was carried out on the basis of previously described prognostic variables to calculate the 5-year risk of SCD. Blood samples were taken from all patients to measure serum galectin-3 levels. A statistical significance level of P < 0.05 was accepted in all tests.We found that there was a significant correlation between the estimated 5-year risk of SCD and serum levels of galectin-3.Galectin-3 may be an inexpensive and easily accessible parameter to predict arrhythmia risk. In addition, it can be used to determine antiarrhythmic prophylaxis as a predictor of an arrhythmia storm in implantable cardioverter defibrillator-implanted patients who are not available for magnetic resonance imaging.