The effect of the initial degree of crystallinity on the isothermal crystallization kinetics from the melt of nylon 6 has been examined. The investigations were carried out in the conditions which allow to maintain a “crystalline memory.” For the investigations, dilatometric and microscopic methods were used depending on the temperature range used. It has been found that for samples of initial crystallinity up to 15% there exists a possibility of the growth of spherulites either from the sporadic or simultaneous nucleation depending on the crystallization temperature. For samples with initial degree of crystallinity higher than 15% the growth of spherulites occurred always from the predetermined nuclei within the investigated range of the crystallization temperature. The crystallization rate of the samples increased with rise in initial degree of crystallinity of the samples.