New binary systems consisting of benzylsilane(stannanes) and aminium salts initiate radical polymerization. Polymerization of vinyl monomers such as methyl methacrylate and butyl acrylate proceeded under mild conditions to afford the corresponding polymers in moderate to excellent yields. Polymerization of styrene resulted in the formation of oligomers. In contrast, the aminium salts inhibit or retard the radical polymerization of such vinyl monomers. The mechanism may involve initial single electron transfer from a benzylsilane(stannanes) to an aminium salt followed by C-Si bond cleavage to give a benzyl radical, which initiates radical polymerization.