Objective To summarize the surgical treatment strategies and the clinical outcomes of hypertrophic obstructive cardiomyopathy (HOCM) with severe mitral regurgitation. Method We retrospectively analyzed the clinical data of 23 patients of HOCM with severe mitral regurgitation in our hospital from January 2004 through January 2014 year. There were 14 males and 9 females, aged from 15-71(50.2±15.4) years. The preoperative left ventricular outflow tract gradient (LVOTPG) of these patients was 75-161(98.1±19.3) mm Hg. And the septal thickness was 25.8±2.8 mm. All 23 patients had at least moderate mitral regurgitation and systolic anterior motion (SAM). All of them had extend septal myectomy (extend Marrow procedure) and mitral valve repair(MVP),while 4 patients with atrial fibrillation had left atrial ablation and left atrial appendage operation. Results All patients were successfully operated. The left ventricular outflow tract pressure gradient was 16-39(26.9±4.9) mm Hg when the cardiopulmonary bypass stopped and SAM phenomenon was completely eliminated. Except for 2 mitral valve patients with trace amounts of regurgitation, 1 patient with mild regurgitation, the other 20 patients of mitral regurgitation were completely corrected. All patients survived after operation and only 1 patient suffered from transient complete atrioventricular block and then back to normal sinus rhythm. A long-term follow-up from 6 months to 126 months with an average of 53.1±34.9 months showed no late postoperative death. No mitral regurgitation need reoperation. Two patients had mild reflux. Four patients were of trace reflux. The left ventricular outflow tract the maximum pressure gradient was less than 42 mm Hg. The thickness of interventricular septum dropped from preoperative 25.8±2.8 mm to postoperative 14.1±1.3 mm (P<0.001) . No recurrence was noted in the 3 patients with atrial fibrillation. And one patient still had paroxysmal atrial fibrillation. Long term follow-up of the patients' symptoms disappeared or with only mild symptoms. And quality of their life improved significantly. And there was no long-term complication, reoperation, or death. Conclusions The extensive septal myectomy can completely dredge left ventricular outflow tract stenosis and eliminate SAM phenomenon. The mitral valve repair can correct mitral regurgitation. The comprehensive surgical treatment strategy can achieve a good long-term therapeutic effect.