The kinetics of molecular‐beam epitaxy are examined by means of Monte Carlo simulations in combination with a new approach for monitoring surface growth, i.e., by calculating the evolution of the surface step density. The evolution of the step density is shown to have a remarkable correspondence to that of the measured reflection high‐energy electron diffraction (RHEED) specular spot intensities for III‐V semiconductor compounds. We study growth in a variety of systems, including flat and stepped surfaces, as a function of substrate temperature and draw several conclusions concerning the relation between RHEED measurements, kinetics, and growth quality. The range of validity of the kinematic approach to RHEED is discussed and the importance of multiple scattering in the high step density regime is highlighted.