The structures of cis-and trans-2-(4-tert-butylcyclohexyloxy)-1, 3, 5-trinitrobenzene, C16H21N3O7,(I) and (II), respectively, were determined at low temperature in order to obtain accurate structural parameters for comparison purposes. The Calkyl—Oether bond distances are 1.497 (2) and 1.491 (2) Å for (I) and (II), respectively.