Several experimental observations are reported on the free radical polymerization of hydroxyethyl acrylate (HEA) in its co- and ter-polymerization with styrene (Sty) and ethyl acrylate (EA) initiated by 2,2＇-azobisisobutyronitrile (AIBN) in bulk. Reactivity ratios were estimated for the system Sty/HEA using the error in variables model (EVM). Kinetic studies over the full conversion range investigated the effects of feed composition, initiator concentration and temperature. Limited observations are reported for the Sty/HEA/EA terpolymerization on the effect of varying HEA levels.