Ruthenium-catalyzed Alder ene reactions between diynes and triynes with terminal alkenes gave the corresponding enynes and enediynes with high regio- and site-selectivity. The selectivity profile clearly indicates that one of the alkynyl moieties of 1,3-diynes not participating in the reaction determines the regiochemistry, whereas the interplay between steric hindrance and polar substituents at the propargylic sites determines the site-selectivity.