Solid-state proton NMR free induction decay (FID) during isothermal (394 K)crystallization from a molten polyethylene sample has been investigated. On the basis of deconvolution of the FID signal, three different: phases are assigned and their relative distribution during crystallization determined. The results are discussed in light of the Avrami model. The formation of the crystalline phase during the primary crystallization time regime increases approximately with the square root of crystallization time; Kinetic data regarding the crystallization process are obtained and discussed.