In the main molecule of the title compound, C21H18Br3N3·CH2Cl2, the triazinane ring adopts a chair conformation with three 4-bromophenyl substituents, two in diaxial positions and the third in an equatorial arrangement (eaa). The torsion angles around the N—C bonds in the triazinane ring are in the range 55.6 (5)–60.1 (5)°. The structure can be described as being built up of alternating layers along the b axis with the CH2Cl2 solvent molecules sandwiched between these layers. No classical hydrogen-bonding interactions are observed in the crystal structure.