The P atom in the title molecule, C24H28N3O2P, is in a distorted tetrahedral P(=O)(N)(N)2 environment. The phosphoryl group and the NH unit adopt a syn orientation with respect to each other and the N atoms have sp2 character. The P-N bonds in the P(O)[N(CH3)(CH2C6H5)]2 unit are shorter than the P-N bond in the C(=O)NHP(=O) fragment. An intramolecular C-H...O hydrogen bond occurs. In the crystal, pairs of P=O...H-N hydrogen bonds form centrosymmetric dimers. C-H...O contacts are also observed. Four C atoms of two benzene rings are disordered over two alternative sites with an occupancy ratio of 0.523 (12):0.427 (12).