Most of the Small Size Effects that take place in epitaxies used in advanced CMOS are reviewed. The most common one is the faceting that is a consequence of different deposition kinetics of the dense crystal planes. On the other hand, when considering small areas, the deposition rate is not a constant and the effective thickness depends on the pattern size and orientation. Thus, the concepts of “time-nonlinear kinetics” or “anisotropic loading effect” have been proposed. These epitaxies are also very sensitive to temperature. Thermal rounding takes place at temperatures as low as 600-625°C. Moreover, with higher thermal budgets, surface energy is capable, as a function of boundary conditions, to create instabilities such as Plateau-Rayleight ones or on the contrary to stabilize the Stranski-Krastanov ones. Finally, the importance of these mechanisms is illustrated in two CMOS applications: thermal rounding and anisotropic loading in SiGe channels and faceting in elevated sources/drains.