Surgery has been the only therapeutic option in patients with hypertrophic obstructive cardiomyopathy who are resistant to drug treatment and sequential pacemaker therapy. I describe a novel catheter-based technique that may replace surgical myocardial reduction in some patients. The technique aims at selective destruction of the hypertrophied part of the left side of the intraventricular septum. If temporary occlusion of the first major septal artery is shown to reduce the intraventricular pressure gradient significantly, absolute alcohol is injected through the inflated balloon catheter to produce a localised infarct. In the first three patients treated with this method, the size of the septal infarct was sufficient to eliminate any subaortic stenosis immediately. Clinical improvement has been maintained up to 12 months. Non-surgical reduction of the septum in hypertrophic obstructive cardiomyopathy warrants further clinical evaluation.