Abstract: Stable emulsions of ethylene homopolymers and copolymers having controlled molecular weight and relatively small particle size are formed by polymerizing ethylene and/or ethylene with another alpha unsaturated monomer in an aqueous medium in the presence of a water soluble persulfate initiator, an anionic emulsifier, nonionic emulsifier or most desirable a mixture of anionic and nonionic emulsifiers and a minor but effective amount of an alkyl mercaptan having from about 4 to about 20 carbon atoms. The resulting stable emulsions exhibit improved compatibility, stability and performance when formulated in various coating compositions such as latex paints and floor polishes.