The title compound, C20H21ClN2O5, has potential calcium modulatory properties. The 1,4-dihydropyridine ring has the usual shallow boat conformation. The 2-chloro-5-nitrophenyl ring is oriented such that the chloro substituent is in a synperiplanar orientation with respect to the 1,4-dihydropyridine ring plane, while the nitro substituent sits over the 1,4-dihydropyridine ring. The cyclohexenone ring has a conformation that is approximately half-way between that of an envelope and that of a half-chair. The molecules are linked into chains by intermolecular N-H...O hydrogen bonds.