Desflurane (DES)-induced preconditioning is mediated by large-conductance calcium-activated potassium channels (BKCa). Whether BKCa are involved in anaesthetic-induced post-conditioning is unknown. We tested the hypothesis that DES-induced post-conditioning is mediated by BKCa upstream of the mitochondrial permeability transition pore (mPTP). Pentobarbital-anaesthetized male C57Black/6 mice were subjected to 45 min coronary artery occlusion (CAO) and 3 h reperfusion. Animals received either no intervention or dimethylsulphoxide (DMSO, 10 µl g–1). DES (1.0 MAC, 7.5 vol%) was administered for 18 min, starting 3 min before the end of CAO. The following agents were given either alone or in combination with DES: the BKCa activator NS1619 (1 µg g−1), the BKCa inhibitor iberiotoxin (IbTx, 0.05 µg g−1), the mPTP opener atractyloside (ATRA, 25 µg g−1), and the mPTP inhibitor cyclosporine A (CYC A, 10 µg g−1). Infarct size (IS) was determined with triphenyltetrazolium chloride and the area at risk with Evans Blue, respectively. IS in control animals was 48(6)%. Neither DMSO, IbTx nor ATRA affected myocardial IS. DES alone or NS1619 alone or the combination reduced IS (P<0.05), CYC A alone or in combination with IbTx or DES also reduced IS (P<0.05). DES-induced reduction of myocardial IS was completely abolished by IbTx and was partially blocked by ATRA and ATRA partially blocked IS reduction by NS1619. These data suggest that DES-induced post-conditioning against myocardial infarction is mediated by BKCa and mPTP. Cardioprotection by BKCa activator NS1619 might occur, at least in part, independently of mPTP.