Abstract Background Malnutrition has been demonstrated as a predictor for unfavorable clinical outcomes in chronic heart failure, and may affect patients with pulmonary arterial hypertension (PAH). The Mini Nutritional Assessment (MNA) is a reliable indicator for nutritional status assessment, but its relationship with mortality risk and hospitalization in PAH patients has not yet been investigated. Purpose The study aimed to determine whether the MNA has prognostic value in stable patients with PAH. Methods A prospective multicenter study was performed. All patients completed the MNA at study entry in outpatient clinic or during planned hospitalization. The primary endpoint was all-cause mortality. Secondary end-point was the composite end-point of all cause death or PAH-related hospitalizations. Patients with malnutrition (MNA ≤17 points) or at risk of malnutrition (MNA 18-23,5 points) were considered as having abnormal nutritional status for statistical analysis. Results 182 PAH patients were included to the study (mean age 60 ± 17 years; 73% females; 57% idiopathic PAH). Abnormal nutritional status was identified in 68 (37%) patients. Median and the range of follow up period was 23 months and 0–32 months, respectively. 34 (18.7%) patients died, 53 (29.1%) were hospitalized due to PH, and 57 (31.3%) achieved the composite secondary end-point. Kaplan-Meier survival curves revealed significant differences in overall survival between patients with abnormal MNA and normal MNA, p <0.0001, and significant differences in composite risk of death and PAH-related hospitalization, p=0.02. In the multivariate Cox regression analysis including age, sex, and main risk factors (COMPERA 2.0 score, TAPSE/PASP, right atrial pressure, cardiac index, mix oxygen saturation), abnormal MNA remained significantly associated with all-cause mortality (HR 2.86 [95%CI: 1.29–6.38], p=0.01) and the composite end-point HR 2.39 [95% CI: 1.05–5.42], p=0.04) in PAH patients. Conclusions Using MNA as a routine screening tool allowed the detection of abnormal nutritional status in more than one third of PAH patients. Nutritional status assessed by the MNA was an independent predictor of all-cause death and the composite end-point of all-cause death and PAH-related hospitalization in patients with PAH.