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Reactions of alkenylsilanes (alkenyl 2-propenyl, vinyl, allyl) with neutral and cationic palladium aryl complexes Pd(C6F5)X(NCMe)2 (X Br, 1; Cl, 2), Pd(C6F5)(acac)(NCMe) (acac acetylacetonate, 3), and Pd(C6F5)(bipy)(S)ClO4(S acetone, 4) were studied. The compounds obtained were substituted alkenylsilanes (formed via Heck substitution) and desilylated olefins (formed by transmetalation followed by reductive elimination or by insertion followed by -SiMe3elimination). The analysis of the structure of the final organic products provides a quantitative assessment of the importance of these competing pathways. Transmetalation to palladium was found to be a minor pathway in all cases, whereas insertion of the double bond into the Pd−C6F5bond followed by -SiMe3elimination was the major route. The formation of C6F5-substituted alkenylsilanes is favored when an excess of starting alkenylsilane is used.