ABSTRACT. Hypertrophic cardiomyopathy (HCM) is one of the widespread genetically determined diseases of the myocardium, which is accompanied by the development of diastolic and, subsequently, systolic dysfunction of the myocardium. The aim of our study was to evaluate the clinical and instrumental features of patients with hypertrophic cardiomyopathy with impaired left ventricular global longitudinal strain (GLS) and its prognostic value for the development of cardiovascular events in the Ukrainian population of patients with hypertrophic cardiomyopathy. Materials and methods. The data of 35 patients with hypertrophic cardiomyopathy who underwent a comprehensive clinical and instrumental examination with determination of the absolute global longitudinal strain on speckle-tracking echocardiography were retrospectively analyzed. The patients were divided into two groups: Group I (GLS< 14.5) and Group II (GLS≥ 14.5). Results. A decrease in global longitudinal strain was associated with a longer disease duration (8 (5-11) vs 3 (2-5) years, p=0.003), increasing of complaints on irregularity of heart beat (66.7% vs 23.5%, p= 0.018) and weakness (61.1% vs 23.5%, p=0.04), increased systolic blood pressure (SBP) (130 (120-140) vs 110 (100-120) mm Hg, p= 0.009), the absence of patients without signs of heart failure (0 vs 29.4%, p=0.019), an increase in IVRT (106.19±28.62 vs 84.57±27.54 ms, p=0.044) and a greater number of ventricular extrasystoles (17 (4-69) vs 2 (0.5-3), p=0.014). According to the Kaplan-Meier analysis of survival in relation to fatal and non-fatal cardiovascular events or their combination with hospitalization for heart failure, they had significantly worse survival rates (Log-Rank, p=0.016 and p=0.003). Conclusions. Hypertrophic cardiomyopathy patients with poor global longitudinal strain scores were characterized by worse clinical and instrumental data and an unfavorable cardiovascular prognosis.