Epitaxial Bi/Sb superlattices have been grown by molecular beam epitaxy on CdTe(111)B substrates. The superlattice modulation wavelength was in the range of 20-200 Angstrom. Structural properties have been investigated using in situ reflection high-energy electron diffraction (RHEED), theta - 2 theta x-ray diffraction (XRD) analysis, and high-resolution transmission electron microscopy (TEM). The streaked RHEED patterns of Bi on Sb (or Sb on Bi) with clear Kikuchi lines indicate layer-by-layer growth with good epitaxial layer quality. The narrow XRD rocking curves for the central and the satellite peaks suggest that the interfaces are very sharp and that the superlattice periods do not fluctuate, which is demonstrated in this article by cross-sectional TEM.