Polysulfides with narrow polydispersity and variable chain length and density of polymerizable units have been synthesized through the use of a methacrylate-bearing and thiol-reactive compound as an end-capper for episulfide anionic polymerization. These macromonomers have been photopolymerized to yield materials with controlled cross-linking density, which translates into a controlled number of cross-links, branching points, and dead-ends. The resulting networks show elastomeric behavior that can be easily described through a simple affine chain model; in the analysis of the network behavior we here also present the calculation of a solvent-independent parameter for rationalizing the behavior of the Flory-Huggins parameters. These materials combine simple preparation (-> in situ processes), easy description of the mechanical properties, and responsiveness (to oxidationnot studied here), features that could make them attractive for biomedical applications.