We extend the theoretical model of recrystallization of a-Si films induced by pulsed laser irradiation and determine c-Si cluster distribution in the solid phase and we discuss the possibility of nanocluster formation in the a-Si thin layer. Our theory is based on the description of nucleation and growth of the crystalline phase in molten Si during fast heating and cooling processes. We are able to describe nonequilibrium solidification, including the distribution of nanocrystals as a function of laser pulse energy. Calculations of temperature distribution during recrystallization processes and the kinetics of crystalline phase formation show that nucleation of c-Si in l-Si must be taken into account in simulations of recrystallization of a-Si induced by high energy density pulsed laser irradiation (>200mJ/cm(2)). The presence of nanoclusters in the Si layer is possible if recrystallization starts from the strong supercooled l-Si, e.g., if a-Si is melted immediately.