The crystal and molecular structure of 4′-cyanophenyl-4-n-butoxybenzoate, which exhibits a monotropic nematic phase, has been determined using single crystal X-ray diffraction data. The crystals belong to the orthorhombic system, Pccn, a = 35.872(8) Å, b = 11.331 (3) Å, c = 7.773 (2) Å, Z = 8. The structure has been solved by direct methods and refined to an R-value of 0.0502 with Fo> 2σ (Fo). The molecular structure shows that the butoxy group is extended in the gauche-conformation. The long molecular axes are arranged parallel to [100] and lie in y ≈ 0.11, 0.39, 0.61 and 0.89. In addition to that, the molecules are arranged in layers which are perpendicular to the a-axis have a thickness of a/2 (≈ 18 Å). Cyano-cyano contacts, N… N′ ≈ 3.54 Å, are found.