Abstract Introduction Pulmonary arterial hypertension (PAH) is a rare chronic disease that, as it progresses, contributes to decreased ability to perform daily activities, deterioration of physical and mental well-being and social functioning. Patients with PAH experience anxiety and depression-like disorders that directly affect their quality of life. In view of the above, it is necessary to determine the determinants that affect the deterioration of mental functioning in this group of patients. Purpose The aim of the study was to determine the prevalence of anxiety and depression and their determinants. Material and methods The study included 89 patients , pulmonary arterial hypertension (PAH), who participated in the Therapeutic Treatment of Pulmonary Arterial Hypertension program by the National Health Service. Patients were asked to complete a standardized questionnaire (HADS) to assess Anxiety and Depression and a self-report questionnaire assessing sociodemographic factors and severity of symptoms. Medical data were taken from the hospital registry. Results In the study group, the mean anxiety score (HADS-A) was M=5.33 (SD=3.31), and the mean depression score (HADS-D) was M=4.4 (SD=3.78), indicating their low level of severity. Significant levels of the studied mood disorders are observed in one in five patients covered by the NHF drug program. Factors significantly (p<0.05) correlating with the severity of anxiety symptoms were chest pain (r=0.343), weakness (r=0.256), fatigue (r=0.327), MWT score 6 (r= -0.266), and arrhythmias (r=0.42). In addition to the above-mentioned factors, significant correlations (p<0.05) were obtained with the severity of depressive symptoms, for such factors as WHO FC Class (r=0.427), eldery age (r=0.263), NT-pro BNP (r=0.239). Conclusions Drug and depressive disorders in the study group of PAH patients are not common and may affect one in five patients (study participants on PAH treatment). The occurrence of anxiety disorders correlates with many PAH symptoms, sociodemographic and clinical factors. Learning about the factors associated with the occurrence of mental disorders can help to better identify them and prevent their occurrence.