A new monofunctional BIS-GMA monomer, 4-(2-phenyl isopropyl)-3-phenoxy-2-hydroxy propyl methacrylate (monofunctional-BIS-GMA, hereafter abbreviated as MF-BIS-GMA) was synthesized as an adduct of 4-cumylphenol and glycidyl methacrylate for use as a dental monomer. The new monomer was characterized by FTIR, H-1, C-13 (attached proton test, APT), UV, HPLC, and GPC. The viscosity and solubility of the new resin are also presented. The results were compared with the difunctional analog, BIS-GMA (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)]phenyl propane), which is commercially available and currently used in dental restorative materials. Both monomers were light-cured using 0.3% camphorquinone and 0.75% 2-(dimethylamino)ethyl methacrylate as photoinitiators. The extent of monomer conversion and the potential for residual monomer leachability were compared between the two cured resins. The monofunctional resin was found to yield higher monomer conversion values (74 vs. 39%) and lower leachable components (0.03 vs. 30.6 mol %) than those of the difunctional analog.