Echocardiography is the best technique to diagnose, evaluate, follow-up and guide the treatment of hypertrophic cardiomyopathy (HCM). Diagnosis of HCM depends on left ventricular wall thickness ≥15 mm. Also noted are mitral valve systolic anterior motion, an- teriorly positioned mitral valve leaflet coaptation, anomalous anterior insertion of papillary muscles, and diastolic dysfunction. Resting left ventricular outflow tract (LVOT) gradient occurs in 25% of patients and provocable gradients may be demonstrated in more than half of patients. Echocardiography is important for sudden death risk assessment; patients with a wall thickness more than 30 mm ha- ve a higher risk of sudden cardiac death, as often as 2%/year. Two thirds of the symptomatic obstructed patients can be successfully managed long term with medical treatment alone (beta-blockers, disopyramide, verapamil) guided by transthoracic echocardiography (TTE) response and follow-up. Obstructed patients, who fail medical therapy, are usually offered invasive treatment: surgical septal myectomy, alcohol septal ablation, or DDD pacemaker. Preoperative TTE is a necessary guide for the surgeon in planning the opera- tion. It gives the surgeon precise measurements of septal thickness, mitral valve leaflets length and floppiness and papillary muscle anomalies. Intraoperative transesophageal echocardiography is a very important tool for evaluating surgical results. Persistent SAM, resting outflow gradient more than 30 mm Hg or more than 50 mmHg with provocation, moderate to severe mitral regurgitation are in- dications for immediate revision. For patients > 40 years old, and also not suitable for surgery because of comorbidities, alcohol sep- tal ablation is viable alternative therapy for relief of obstruction and improvement of symptoms. Echocardiography is a valuable tool to choose the site of ablation (using myocardial contrast echocardiography), as well as for evaluation of results.