Atom transfer radical polymerization (ATRP) performed in ab initio emulsion provides access to well-defined polymers in a low-cost, eco-friendly environment. Herein, photoinduced ab initio emulsion ATRP of various (meth)acrylate monomers is reported. The polymerization rate increased with the solubility of the monomer in water. Well-controlled (co)polymerizations were achieved under violet light and low catalyst loading, even in an open-to-air system through enzymatic degassing.