Herein reported is a dehydrative allylation reaction of 2-alkylbenzophenones with allylic alcohols promoted by light and palladium. Photoirradiation of 2-alkylbenzophenones generates nucleophilic species which couple with allylic alcohols. Mechanistically, in-situ generated carboxylic acid is likely to activate allylic alcohols to facilitate the palladium-catalyzed allylation reaction.