Background. Little is known about self-reported barriers to performing physical activity (PA) in patients with pulmonary hypertension. Objectives. Identify the barriers to performing PA and whether there is a correlation between these barriers and functional capacity and quality of life. Methods. A single-center prospective observational study (March 2016 - August 2021) with 50 patients with pulmonary arterial hypertension (PAH) and 20 with chronic thromboembolic pulmonary hypertension (CTEPH). All patients performed the six-minute walk test (6MWT) and answered the Barriers to Physical Activity Questionnaire (BPAQ) and the SF-36 questionnaire. The correlation analysis (Spearman coefficient) was performed between the BPAQ score and the clinical variables, 6MWT, and quality of life. The project was approved by the institution's ethics committee; patients signed the informed consent form. Results. In both groups, unwillingness to exercise and lack of energy were the most frequently encountered barriers: 64% and 32% (PAH), and 35% and 60% (CTEPH). Lack of structure was often mentioned as well (CTEPH:35%). There was no difference between groups (p>0.05). The item vitality (SF-36) showed a moderate correlation with lack of energy, lack of will, and lack of structure (BPAQ), and a weak correlation with social influence. Unwillingness (BPAQ) showed moderate correlations with all SF-36 domains, except pain. Associations were also found between lack of desire (BPAQ) and reduced walking distance (6MWT). Conclusions. Lack of will and/or energy were the most cited barriers to practicing physical exercises by patients with PH. There were correlations between perceived barriers with the SF-36 domains and functional capacity.