Background: Coronary heart disease is associated with increased B-type natriuretic peptides ( BNPs), and, although controversial, may cause exaggerated exercise-induced BNP secretion. We investigated BNP in relation to reversible myocardial ischaemia. Materials and methods: Serum N- terminal proBNP ( NTproBNP) was measured before and after an exercise electrocardiogram test ( ETT) in 14 patients with and 45 patients without exercise- induced myocardial ischaemia. Statistical analysis was carried out on logarithmically transformed data. Results, however, are pre- transformed data. Results: NT- proBNP increased with exercise both in ETTpositive patients ( mean ( SD) 71.4 ( 41.2) v 76.8 ( 44.0) ng/ l; p, < 0.001) and ETT- negative patients (54.0 (61.2) v 60.1 (69.0) ng/ l; p < 0.001). Pre-exercise and post-exercise NTproBNP were higher ( p, < 0.05) in ETT- positive than in ETT-negative patients. Incremental NT- proBNP was similar in ETTpositive ( 4.7 ( 4.2) ng/ l) and ETT- negative ( 6.2 ( 8.6) ng/ l) patients. Conclusion: Serum NT- proBNP concentrations are higher in patients with exercise- induced myocardial ischaemia than in those without. Exercise- induced electrocardiographic myocardial ischaemia, however, is not associated with exaggerated BNP secretion.