We show by Kinetic Monte Carlo simulations that the leapfrog diffusion mechanism leads to a selective faceting and to a nonmonotonic behavior of the roughness during the epitaxial growth of missing-row (1 1 0) surfaces. At intermediate temperatures, (3 3 1) and (1 1 1) nanofacets are formed in equal proportions, while at high temperatures the surface presents almost only (1 1 1) facets. An analytical formula for the onset temperature of the selective faceting is derived. (C) 2004 Elsevier B.V. All rights reserved.