In Taiwan, patients with pulmonary hypertension (PH) related to chronic obstructive pulmonary disease (COPD) are most common PH population (group 3). However, efficacy of medical treatments and optimal prevention methods in this group remain uncertain. Statins such as indirect RhoA/Rho-kinase inhibitors influence one of key signalling pathways that promote PH onset. In this study, we explored protective effects of statins against PH in COPD patients using database from Taiwan National Health Insurance programme from 2002 to 2017. The main outcome was the risk of PH. The Cox proportionalhazards model and the Fine and Gray model were used to adjust covariate and competing risks to estimate the subdistribution hazard ratios (sHRs). 553,617 newly diagnosed COPD patients were stratified by statin users (n = 41,168) and statin nonusers (n = 512,449). After 1:1 propensity score matching of statin users (n = 41,163), and 41,163 statin nonusers were included for outcome analysis. Statin users had a 22% lower risk of PH than nonusers (sHR: 0.78, 95% confidence interval: 0.65-0.94). During subgroup analysis, taking higher daily doses and for a longer duration displayed a more significantly reduced risk of PH (both P for trend <0.001). Statins may have a protective effect against PH that is dose-and time-dependent. Pulmonary hypertension (PH) is a pathophysiologic and hemodynamic condition that increases the pressure level in the pulmonary arteries, veins and/or capillaries. Eventually, under these conditions, the need for the heart ventricles to contract more and more to pump blood through the lungs and heart can result in heart failure, cardiovascular diseases, or respiratory function loss 1. In 2018, the sixth World Symposium on PH (WSPH) released an updated statement separating PH patients into five groups according to clinical presentation, hemodynamic characteristics, pathophysiology, and therapeutic strategy 2. The incidence of PH is about 2.4 cases per million adults per year in the United States 3-6. One Taiwan prevalence survey suggested the patients with PH related to COPD (group 3 in the WSPH classification scheme) is the most common PH population in Taiwan 7. Of interest, while the severity of PH among patients in group 3 may be less than that in other PH groups, the three-year survival rate in this group is the lowest across all five PH groups 8. This lower survival rate might due to a lack of evidence and efficacy regarding the use of current medical treatments for PH including supportive therapy and certain drugs in PH related to COPD. Besides, there has been no clear prevention strategy revealed that can reduce the risk of PH in COPD patients; currently, only long-term oxygen therapy can improve symptoms. Given these facts, the development of a new treatment in this population is necessary 9,10 .