Abstract Background and aims In this retrospective analysis of a nation-wide registry on pulmonary arterial hypertension (PAH), group IV and V, we aimed to evaluate the clinical, echocardiographic,haemodynamic and neurohumoral predictors of morbidity and mortality. Methods This study included 903 patients enrolled from 24 cardiology centers participating in the RegiStry on clInical outcoMe and sUrvival in pulmonaRy hypertension Groups (SIMURG II). ESC/ERS 2022 risk scoring model was used for risk predictions at baseline assessment. Composite endpoint (CEP) definitions were adopted from the SERAPHIN and GRIPHON trials. Results Age was 51.27 + 21.37 years, and 72 % of patients were female. Incident cases were noted in 65.9 % of overall group. Idiopathic PAH (IPAH), PAH-associated with congenital heart diseases (CHD-PAH), PAH-associated with connective tissue diseases (CTD-PAH), porto-PAH, Group IV and V pulmonary hypertension (PH) were documented in 33 %, 33.5 %, 12 %, 1.6 %, 20 % and 1.7 % of overall patients, respectively. Background mono and dual targeted combinations, and sequential dual or triple combinations were noted in 17 %, 57 % and 26 % of patients, respectively. Baseline low-, intermediate- and high-risk were noted in 1.2 %, 14.1 %, and 84.7 %, respectively. Median follow-up time was 867 (412-1667) days. Overall rates of mortality and CEP were 26 % and 39%, respectively. Prevalent versus incident cases were associated signifinatly lower mortality and CEP rates (p=0.028 and p=0.024, respectively). Mortality and CEP rates were 31 % and 44 % in IPAH, 20 % and 39 % in CHD-PAH, 31 % and 43 % in CTD-PAH, and 25 % and 30 % in group IV patients, respectively. CHD-PAH compared with other groups was associated with a higher Kaplan-Meier (K-M) survival and CEP-free survival (p< 0.0001 and p=0.00023, respectively). Survival was associated with prevalent versus incident status, baseline functional class (FC) and six-minute walk distance (6MWD) in all subgroups (p<0.0001 for all), NT-brain natriuretic peptide and right atrial area in IPAH,CHD-PAH and CTD-PAH, and mixed venous O2 saturation % in IPAH and CHD-PAH (p varying from <0.0001 to 0.027). But, TAPSE / systolic pulmonary artery pressure ratio, right atrial-pulmonary capillary wedge pressure difference, pulmonary vascular resistance and its ratio to systemic vascular resistance, cardiac index were not related with survival. Baseline high versus intermediate /low risk was associated with a lower overall survival and CEP-free survival ( p=0.03 and p=0.003, respectively). Male sex [hazard ratio(HR):1.73;1.2-2,51,p = 0.004], 6MWD (p<0.001), FC III/IV (HR: 2.52;1.47-4.32, p<0.001) and baseline low-risk (HR:0.37;0.21-0.65, p<0.001) were independent predictors of mortality. Conclusions Our nation-wide data revealed current insights regarding the clinical, echocardiographic,haemodynamic and neurohumoral predictors of morbidity and mortality in PAH and group IV PH.