Relativistic DFT calculations, performed for Sb layers adsorbed on the Mo (112) surface, have revealed a strong interaction of Sb adatoms with the surface. At low coverages, the layer is predicted to form a c (2 × 2) structure, while for a complete Sb monolayer the most favorable structure is the p (1 × 1), which forms despite a minor one-dimensional compressing of the layer in the direction along the Mo (112) surface furrows. This structure is favorable also for complete bilayer and 3-layer films, so that very thin Sb layers reproduce the furrowed structure of the Mo (112) surface. The adsorbed Sb layers cause a significant redistribution of the densities of states, which, however, does not increase enough at the Fermi level to produce any substantial metallization of the film. The spin-orbit coupling causes only minor changes in the band structure, while Sb layer on one face of the Mo (112) slab destroys the inversion symmetry of the adsorption system thus leading to the appearance of the Rashba-type splitting of the bands.