Background: Several studies have reported the electrical characteristics in patients with hypertrophic cardiomyopathy (HCM). However, there are limited data based on a large population, comparing asymmetric versus apical HCM. Methods: Electrocardiography were quantitatively analyzed in patients with HCM in a tertiary referral center. Results:Of 852 patients (age 55.3짹14.2 years, 69.0 % men), 243 (28.5 %) patients had apical HCM, 553 (64.9 %) patients had asymmetric HCM, and 56 (6.6 %) patients had mixed type HCM. Various abnormal findings were found in electrocardiography. QT prolongation, QRS widening, PR prolongation, and pathologic Q wave are frequent in patients with asymmetric HCM, while left ventricular strain is frequent in patient with apical HCM (see figure). There is no significant difference in prevalence of atrial fibrillation (11.0 % versus 7.1 %, p=0.17) between apical and asymmetric HCM. Early repolarization, defined as more than 0.1 mV in inferior or lateral lead, was found in 11.1 % in apical HCM, and 11.6 % in asymmetrical HCM (p=0.19). Conclusions: In the large cohort of HCM, QT prolongation, QRS widening, PR prolongation, and pathologic Q wave were prevalent in patients with asymmetric HCM.