J-point elevation in the inferior and/or lateral leads is associated with an increased incidence of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM), although the exact underlying mechanism is not known. As severe left ventricular hypertrophy and late gadolinium enhancement (LGE) are important risk factors for SCD in this population, we aimed to assess whether there was an association between an early repolarization pattern (ERP) and greater left ventricular mass (LVM) and LGE extent among patients with HCM. This was a retrospective cohort study of 85 consecutive patients with HCM who underwent cardiac magnetic resonance (CMR) and had an electrocardiogram without confounders (intraventricular conduction delay, complete left or right bundle branch block, or ventricular paced rhythm). Baseline characteristics and MRI-derived LVM and LGE extent were compared between patients with and without ERP. ERP was present in 9 out of 85 patients (10.6%). Patients with ERP had greater indexed LVM compared to those without (112.5 ± 26.3 vs. 87.8 ± 24.6 g/m2, p = 0.006). Logistic regression analysis revealed a 4.2-fold increase in the odds of prevalent ERP per standard deviation increase in body surface area-indexed LVM (odds ratio 4.2; 95% CI 1.54-11.4, p = 0.005). There were no statistically significant differences regarding LGE extent between groups. ERP is associated with greater CMR-derived LVM among patients with HCM. This finding could partially explain the association between J waves and a higher risk of SCD in this population. There were no differences in LGE extent. Further studies are needed to confirm this association and evaluate the importance of ERP as a marker of increased risk of SCD in HCM.