Crowned chromenes − four novel naphthopyrans (chromenes) bearing monoaza-12-crown-4, -15-crown-5, -18-crown-6, and a noncyclic analogue at the 5-position − were synthesized, and their photochromism in acetonitrile was examined in the presence of alkali and alkaline-earth metal ions. Incorporation of crown ether units to chromene moieties facilitated to a great extent both the thermal isomerization and photoisomerization of the chromene moiety, reflecting the metal-ion-binding ability of the crown ether moiety. Comparison of the crowned chromenes with the cor-