Polyethylene blends were studied by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Binary blends of commercial linear polyethylene (LPE) with two low-density polyethylenes (LDPEs) of melt indexes, about 20 and about 0.27 g/10 minutes, were investigated. The blends, with 10% and 50% LPE contents, and the pure LPE were isothermally crystallized at 124°C for up to 48 h under solid-liquid phase segregation conditions. Double melting endotherms were obtained for the blends. Results show that, despite differences in crystallization kinetics between both types of blends, the same depression in the LPE melting temperature and approximately the same LPE crystal thicknesses were found for the blend compositions. In addition, the extent of occurrence of lamellar thickening in LPE during crystallization is a function of its content in the blend.