A donepezil-containing patch preparation is provided whereby production of donepezil-related substances in the pressure-sensitive adhesive layer is suppressed. A stabilizer comprising at least one or more species selected from the group consisting of ascorbic acid, metal salts or esters thereof, isoascorbic acid or metal salts thereof, ethylenediamine tetraacetic acid or metal salts thereof, cysteine, acetylcysteine, 2-mercaptobenzimidazole, 3(2)-t-butyl-4-hydroxyanisole, 2,6-di-t-butyl-4-methylphenol, tetrakis[3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionic acid]pentaerythritol, 3-mercapto-1,2-propanediol, tocopherol acetate, rutin, quercetin, hydroquinone, metal salts of hydroxymethanesulfinic acid, metal metabisulfite salts, metal sulfite salts and metal thiosulfate salts is blended in a donepezil-containing pressure-sensitive adhesive layer provided on at least one side of a support.