We aimed to investigate relations between PAP increase on exercise and long-term evolution of pulmonary hypertension and survival. 43 COPD pts were investigated. Initially they with mild pulmonary hypertension and abnormally high increase in PAP on exercise (40 W, 5 min). All pts were followed-up for 3-5 years. During follow-up 21 pts. died (group I), mean survival time was 28 +/- 17 month, and 22 survived (group II), mean observation period was 59 +/- 22 month. Survivors were recatheterized after 3-7 yrs (mean 5 yrs). PAP increased by 3.4 +/- 4.9 mm Hg and correlated better with initial PAP (r = 0.91, p < 0.001) than with delta PAP on exercise (r = 0.61, p < 0.02). Survivors differed from dead in FEV1 (1.59 +/- 55 vs 1.17 +/- 0.33 L, p < 0.02), VC (3.54 +/- 1.0 vs 2.8 +/- 0.84 L, p < 0.02), resting PaO2 (39.1 +/- 9.0 vs 46.3 +/- 11.5 mm Hg, p < 0.05) resting heart rate (82.5 +/- 13.6 vs 93.8 +/- 16.1 beats/min p < 0.02) resting PAP (20.7 +/- 8.2 vs 32.3 +/- 13.2 mm Hg, p < 0.002), and resting PW (7.6 +/- 2.0 vs 11.6 +/- 7.4 mm Hg, p < 0.05).