Abstract We aimed to evaluate the coronary flow reserve (CFR) before and after percutaneous balloon mitral valvuloplasty (PBMV) in patients with mitral stenosis (MS) and its association to clinical events. A prospective study included 45 patients with mitral stenosis candidate for PBMV (age 38 ± 19 years, 27 were females) and 20 with matched age and sex, healthy controls were included in the study. Noninvasive CFR was measured using transthoracic echocardiography and utilizing adenosine stress echocardiography (0.14 mg/kg/min) before PMBV, and one weak post PBMV using multi-tract balloon valvuloplasty technique. CFR was significantly lower in patients with MS compared to controls (P < 0.001). Moreover the CFR was significantly increased post-PBMV (P < 0.001) associated with significant increase in LVEF% (P < 0.05), decrease in systolic pulmonary artery pressure (P < 0.001), significant increase in TAPSE (P < 0.001). CFR was significantly correlated with the degree of change (Δ) in MVA, TAPSE, LVEF%, mean mitral PG and sPAP (r = 0.77, P < 0.001, r = 0.63; P < 0.001; r = 0.42; P < 0.05; r = −0.81; P < 0.001 and r = −0.65; P < 0.001). Mitral valve stenosis was associated with significantly impaired coronary flow reserve that significantly improved after PMBV. The improved CFR values were significantly correlated with the gain in the MVA and the improvement in the functions of both left and right ventricles.