The 1,5-benzodiazepine ring system exhibits a puckered boat-like conformation for all four title compounds [4-(2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepine, C(21)H(18)N(2)O, (I), 2-(2,3-dimethoxyphenyl)-4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepine, C(23)H(22)N(2)O(3), (II), 2-(3,4-dimethoxyphenyl)-4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepine, C(23)H(22)N(2)O(3), (III), and 2-(2,5-dimethoxyphenyl)-4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepine, C(23)H(22)N(2)O(3), (IV)]. The stereochemical correlation of the two C(6) aromatic groups with respect to the benzodiazepine ring system is pseudo-equatorial-equatorial for compounds (I) (the phenyl group), (II) (the 2,3-dimethoxyphenyl group) and (III) (the 3,4-dimethoxyphenyl group), while for (IV) (the 2,5-dimethoxyphenyl group) the system is pseudo-axial-equatorial. An intramolecular hydrogen bond between the hydroxyl OH group and a benzodiazepine N atom is present for all four compounds and defines a six-membered ring, whose geometry is constant across the series. Although the molecular structures are similar, the supramolecular packing is different; compounds (I) and (IV) form chains, while (II) forms dimeric units and (III) displays a layered structure. The packing seems to depend on at least two factors: (i) the nature of the atoms defining the hydrogen bond and (ii) the number of intermolecular interactions of the types O-H...O, N-H...O, N-H...pi(arene) or C-H...pi(arene).