The transition metal-catalyzed addition of the X-H bond of a carbon, nitrogen or oxygen nucleophile across the C[double bond]C bond of an unactivated alkene (hydrofunctionalization) represents an attractive, atom-economical approach to the synthesis of carbocyclic and heterocyclic molecules and for the elaboration of ethylene and 1-alkenes. We have developed a family of Pt(II)-catalyzed protocols for the inter- and intramolecular hydrofunctionalization of unactivated alkenes with a range of H-X nucleophiles including beta-diketones, indoles, amines, carboxamides and alcohols. These transformations display good functional group compatibility, low moisture sensitivity, and often good generality.