Background Most work with respect to the benefits of exercise training has been performed in chronic obstructive lung disease and is used to support pulmonary rehabilitation. Emerging data indicate that exercise training is likewise beneficial in patients with PH. This review summarizes the evidence supporting the value of exercise testing and training. Methods We performed a systematic review (Medline, EMBASE, LILACS) to identify randomized controlled (RCT) and observational studies reporting the efficacy and safety of a program of exercise training in patients with PH. Two of the authors independently selected studies that met the inclusion criteria and assessed methodological quality using the GRADE approach. Primary outcomes included change in 6 min walking distance (6MWD), quality of life, cardiopulmonary exercise test parameters and safety. Results We selected eleven studies: 3 RTC and 8 cohorts (7 prospective), all with acceptable to high quality (table). The RCTs included 77 patients with mean age 53 years, 68 women (88%), almost all NYHA class II-IV; HAP 35 (45%) and CTEHP 8 (10%); monotherapy in 29% and exercise program with 10-15 weeks of duration. In all studies there was a statistically and clinically significant improvement in 6MWD in the group of exercise; only 2 trials evaluated quality of life, showing improvement in certain domains of SF-36 score; only one trial reported statistically significant changes in VO2mx postexcercise. There were no reports of adverse events related to the exercise programs. The cohorts included 1082 patients with mean age 45 years, most women (754; 69.6%), almost all NYHA class II-IV and with all groups of Nice 2013, with program duration of 15 weeks (3 in hospital and 12 as outpatient). In 7 studies there was a statistically and clinically significant improvement in 6MWD in the group of exercise; quality of life was reported in 6 studies (5 with SF-36, 1 SGRQ), showing improvement in certain domains of SF-36 score and without change in SGRQ score. Three studies reported statistically significant changes in VO2mx postexcercise. The most frequent adverse events were respiratory infection, gastrointestinal symptoms and syncope/presyncope. Conclusions Patients with PH present similar symptoms and systemic derangements as those observed in chronic pulmonary diseases and therefore may improve 6MWT as well as quality of life with the implementation of exercise training as part of their medical care. The current evidence concerning the potential benefits and risks of exercise training is encouraging and provides a basis for further research. (Table Presented).