Although mild pulmonary hypertension (PHT) is known to be associated with increased mortality, its impact on premature mortality is largely unknown.We studied the distribution of estimated right ventricular systolic pressures (eRVSP) among 154 956 adults with no evidence of left heart disease investigated with echocardiography. We then examined individually linked mortality, premature mortality and associated life-years lost (LYL) according to eRVSP levels.The cohort comprised 70 826 men (61.3textpm17.7 years) and 84 130 women (61.4textpm18.4 years). Overall, 85 173 (55.0, 49 276 (31.8, 13 060 (8.4 and 7447 (4.8 cases had an eRVSP level indicative of no (lt;30.0 mmHg), mild (30.0textendash39.9 mmHg), moderate (40.0textendash49.9 mmHg), or severe (>=50.0 mmHg) PHT, respectively. During median 5.7 (interquartile range 3.2textendash8.9) years follow-up, 38 456/154 986 (24.8 individuals died. Compared to an eRVSP lt;30.0 mmHg, age and sex-adjusted hazard ratios for all-cause and cardiovascular-related mortality were 1.90 (95.84textendash1.96) and 1.85 (95.74textendash1.97) respectively, for an eRVSP of 35.0textendash39.9 mmHg. Overall, 6,256 (54 men and 7524 (55 women died prematurely. As a proportion of all deaths, premature mortality rose from 46.79.2% among those with an eRVSP lt;30.0 mmHg versus >=60.0 mmHg with a mean of 5.1 to 11.4 LYL each time. However, due to more individuals affected overall, an eRVSP of 30.0textendash39.9 mmHg accounted for 58340 606/70 019 LYL) and women (47 333/88 568 LYL), respectively.These data confirm that elevated eRVSP levels indicative of mild PHT are associated with increased risk of death. Moreover, this results in a substantive component of premature mortality/LYL that requires more proactive clinical surveillance and management.FootnotesThis manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.Conflict of interest: Simon Stewart reports Senior Principal Research Fellowship from NHMRC Australia, consultancy fees from NEDA, and honoraria for presentations from Novartis Pharmaceuticals, outside the submitted work. David Playford and Geoff Strange report an investigator-initiated grant from Johnson amp; Johnson, during the submitted work. All other authors have nothing to disclose.Conflict of interest: Chan has nothing to disclose.Conflict of interest: Playford has nothing to disclose.Conflict of interest: Strange has nothing to disclose.