Infective endocarditis (IE) is a relatively rare but serious complication of hypertrophic obstructive cardiomyopathy. Currently, antibiotic prophylaxis is not generally recommended in these patients. We report a case of infective endocarditis in a patient after alcohol septal ablation for hypertrophic obstructive cardiomyopathy with residual left ventricle outflow tract obstruction. To the best of our knowledge, this is the first case in the medical literature demonstrating this complication in the late postprocedural period following alcohol septal ablation.