Longitudinal two-dimensional strain deformation is a novel technique which evaluates global and regional left ventricular (LV) function with high reproducibility. The aim of the study was to investigate the global and regional systolic function using this method in patients with pure mitral stenosis (MS). Conventional echocardiography and longitudinal two-dimensional strain analysis were performed in 60 patients (41 ± 5 years, 48 women) with mild to moderate MS (mitral valve area: 1.9 ± 0.5 cm²), and 52 healthy controls (40 ± 7 years, 37 women). For strain analysis standard apical views were obtained, and by using a software system peak systolic strain and strain rate were calculated off-line in each segment. In all, 88% of the segments could be optimally tracked by the software system. Despite normal LV systolic function as assessed by ejection fraction (66 ± 8%), mean global longitudinal strain (GLS) and global longitudinal strain rate (GLSR) were significantly reduced in patients with isolated MS (GLS −17 ± 3.3 vs. −19 ± 2.5%, P = 0.006 and GLSR −1.3 ± 0.3 vs. −1.5 ± 0.3 s⁻¹, P < 0.0001). Regional analysis demonstrated that patients with MS had a significantly reduced longitudinal peak strain and strain rate in all basal, and some mid (inferior, anteroseptal, interventricular septum) segments of the left ventricle. For other segments longitudinal peak strain and strain rate values were similar among the groups. Evaluation of LV systolic function by longitudinal two-dimensional strain deformation identified early abnormalities in MS patients who had apparently normal standard systolic function.