The isothermal crystallization behaviour has been investigated for several compositions of blends between nylon 6 (N6) and the liquid crystal copolyester Vectra using calorimetric and X-ray diffraction techniques. Differences in the crystallization rates have been related to the structural properties of these systems by means of WAXS and SAXS real time experiments using synchrotron radiation. Other kinetic parameters such as the Avrami exponents, the equilibrium melting temperatures, and the interfacial free energies have been determined from the calorimetric data.