A novel type of elastomers with silver nanoparticles (AgNP) as cross-linkers has been obtained by a quantitative one-phase bottom-up procedure based on alpha,omega-dimercapto-poly(cis-1,4-isoprene) (PIP). This telechelic polymer with high cis-content of >80% and near-quantitative fiinctionalization degree has been synthesized in a one-pot procedure by anionic polymerization. It was cross-linked by coordination of the thiol groups to in-situ synthesized AgNP to yield a repeatedly melt-processable elastomer. It was found that the E-modulus increased up to an ideal ratio of AgNP to PIP and decreases drastically with AgNP oversaturation due to decreasing cross-linking density. Swelling experiments were in agreement with these results. The cross-linking of telechelic polymers with metal nanoparticles has been applied to other metals and polymers, leading to cross-linked materials in all cases. Antibacterial properties of the silver-containing elastomers were found by the Kirby-Bauer test.