Abstract: AIM:To compare the changes of plasma brain natriuretic peptide (BNP) levels in patients with congestive heart failure (CHF) or lung-derived heart disease (pulmonary heart disease, PHD) with dyspnea at onset and 1 week after remission. METHODS: Using the whole blood chemiluminescence method, plasma BNP levels in patients with dyspnea were determined at onset and 1 week after remission. RESULTS: At the onset of dyspnea in patients with CHF, plasma BNP levels were significantly higher than those 1 week after remission ［(1997±865) ng/L vs. (184±114) ng/L, P<0.05］. Likewise, at the onset of dyspnea in patients with PHD, plasma BNP levels were also significantly higher than those 1 week after remission ［(679±202) ng/L vs. (145±48) ng/L, P<0.05］. However, at the onset of dyspnea, plasma BNP levels in patients with CHF were significantly higher than those in patients with PHD (P<0.05), but no significant difference was observed between groups at 1 week after remission. CONCLUSION: BNP levels reduce with dyspnea remission. BNP levels can serve as an index in evaluating clinical severity and therapy results. At onset of dyspnea in patients with CHF, the BNP level is significantly higher than in patients with PHD, which can possibly be used clinically in differentiating dyspnea of CHF from PHD.