4-isothiocyanato phenyl 4-pentylbicyclo[2,2,2]octane-1-carboxylate, C21H27O2NS is a nematogen containing an unusual eight membered ring in the rigid core. The compound crystallizes into the triclinic system with a = 9.8969(1) Angstrom, b = 42.911(8) A, c = 9.877(2) Angstrom, alpha = 92.86(2)degrees, beta = 103.79(1)degrees, gamma = 94.43(1)degrees, V = 4051.3(1) Angstrom(3), Z = 2. The data were collected using MoKalpha radiation (lambda = 0.71073 Angstrom) at T = 300K. The structure was solved by direct methods using SHELXS-86 and refined to a final R and wR of 0.0688 and 0.1814 respectively using 2452 observed reflections with I > 2 sigma(I). The structure shows a layered packing down a-axis and imbrication along the other two axes. The crystal structure throws light on the liquid crystalline behaviour of the compound.