Abstract: N-[N-(Tetrahydropyrido[2,3-d]pyrimidinylmethyl) aminomethylbenzoyl]glutamic acid derivatives are antineoplastic agents with an effect on one or more enzymes which utilize metabolic derivatives of folic acid. The compounds can be prepared by allowing a protected aminomethylbenzoylglutamic acid derivative to react with 2-amino-4-hydroxy-6-formylpyrido[2,3-d]pyrimidine, reducing the intermediate Schiff base, and subjecting the intermediate to catalytic hydrogenation. A typical embodiment is (S,S) N-[N-(2-amino-4-hydroxy-5,6,7,8- tetrahydropyrido-[2,3-d]pyrimidin-6-ylmethyl)-4-aminomethylbenzoyl]-glutam ic acid.