This paper reviews polymers with pendant vinyl functionalities focusing on their preparations, characteristics and modifications. Of particular interest are poly(divinylbenzene-co-ethylvinylbenzene) and related crosslinked resins, including some of the commercially available Amberlite resins. Styrenic resins are excellent substrates for the preparation of functional polymers. Modification through the vinyl functionality is generally underutilized and further research in this area as an alternate to more traditional polymer modification techniques such as chloromethylation is encouraged.