We have investigated growth mechanisims and defect formation processes during crystallization from melted Si by using molecular dynamics simulations combined with the Tersoff potential. The melt growth in the [001] direction was rate-limited by a diffusion process of Si to be trapped at the kink sites associated with {111} facets formed at the solid/liquid Si interface, while in the [111] direction the interface was essentially flat and the rate-limiting step was double-layered two-dimensional nucleation on the (111) surface which was fol-lowed by double-step lateral epitaxial growth. Defect formation was found to be initiated by a 5-membered ring created at the interface that gave rise to an interstitial-type defect resembling the ‹110› split interstitial.