In the title mol-ecule, C(19)H(25)N(2)O(2)P, the P atom is bonded in a distorted tetra-hedral environment. The dihedral angle between the two phenyl rings is 89.09 (8)°. The methyl H atoms are disordered over two sets of sites with equal occupancy. The O atom of the P=O group acts as a double hydrogen-bond acceptor of the type (N-H)(2)⋯(O=)P-, forming R(2) (2)(8) rings which are further linked into chains along [010].