A series of substituted 2-pyrrolidinones was evaluated for hypolipidemic activity at 20 and 30 mg/kg/day in CF1 male mice. 4-Phenyl-5,5-dicarbethoxy-2-pyrrolidinone was the most potent compound at 30 mg/kg/day, reducing serum triglyceride levels 52% after 14 days of dosing and serum cholesterol levels 48% after 16 days of dosing. 4-Phenyl-5-carbethoxy-2-pyrrolidinone and 4-phenyl-3,5,5-tricarbethoxy-2-pyrrolidinone also demonstrated significant activity. Those compounds which contained a phenyl substituent were more potent than either the unsubstituted, the alkyl, or the dicarbethoxy 2-pyrrolidinone analogues.