2-Anilino-3-(2-hy-droxy-phen-yl)quinazolin-4(3H)-one-triphenyl-phosphine oxide (1/1).

In the title compound, C20H15N3O2·C18H15OP, the pyrimidinone heterocycle and the fused phenyl ring are inclined at 1.92 (7)°. Only the hy­droxy group is involved in hydrogen bonding, whereas the amino group is shielded from potential acceptors.