Abstract Summary: The reverse atom transfer radical polymerization of butyl methacrylate in miniemulsion, initiated with the redox pair hydrogen peroxide/ascorbic acid and mediated with copper(II) bromide tris[2‐di(2‐ethylhexyl acrylate)aminoethyl]amine is capable of producing well‐controlled high‐molecular weight poly(butyl methacrylate).