We report right ventricular involvement in apical hypertrophic cardiomyopathy (HCMP) in two women and one man, aged from 19 to 44 years-old, who presented different signs from those with left ventricular disease (who have good clinical evolution), with signs and symptoms of severe diastolic restriction, showing great atrial enlargement and two with atrial fibrillation and death due to thromboembolism. The right ventricular involvement in apical HCMP leads to a worst prognosis than isolated left ventricular disease, does not have the typical electrocardiographic changes and presents with ventricular restriction and tricuspid regurgitation.