Pulmonary hemodynamics during exercise may reveal early pulmonary vascular disease and be of clinical and prognostic relevance in systemic sclerosis (SSc). We aimed to assess the prognostic relevance of exercise pulmonary resistances in patients with SSc with no or mildly increased mean pulmonary arterial pressure (mPAP).Are pulmonary resistances at peak exercise independent predictors of mortality in systemic sclerosis?All SSc patients with resting mPAP <25mmHg and at least 1-year follow-up data who underwent symptom-limited exercise right heart catheterization between April 2005 and December 2018, were retrospectively analyzed. Age-adjusted Cox-regression analysis was used to evaluate the association between pulmonary resistances and all-cause mortality.The cohort consisted of N=80 patients (f:m=73:7; age=57 years [IQR 47-67]; follow-up time =10.4 years [IQR 8.5-11.8]). At baseline, resting mPAP ≤20mmHg and 21-24mmHg was found in 68 and 12 patients, respectively. Pulmonary vascular resistance (PVR) and total pulmonary resistance (TPR) at peak exercise were significantly associated with mortality (p=0.006; HR: 2.20 [95%CI 1.26-3.87] and p=0.026; HR: 1.56 [95%CI 1.06-2.29]), while resting PVR and TPR were not (p=0.087; HR:2.27 [95%CI 0.89-5.83] and p=0.079; HR: 1.88 [95%CI 0.93-3.80]). The mPAP/cardiac output (CO) and transpulmonary gradient (TPG)/CO slopes were significantly associated with mortality (p=0.047; HR: 1.14 [95%CI 1.002-1.286] and p=0.034; HR: 1.34 [95%CI 1.02-1.76]) as well. The area-under-the-receiver-operating-characteristics curve for exercise PVR to predict 10-year-mortality was 0.917 [95%CI 0.797-1.000].PVR and TPR at peak exercise, mPAP/CO slope and TPG/CO slope are predictors of age-adjusted long-term mortality in SSc patients with no or mildly increased pulmonary arterial pressure.