The crystallization behavior and structure of polyamide 6 (PA6) nanocomposites containing 3 wt.-% montmorillonite (MMT) were investigated for different cooling conditions using differential scanning calorimetry and X-ray diffraction. In sharp contrast to PA6 and other semicrystalline polymers, increased cooling rates resulted in higher crystallinity of PA6/MMT. The. highest crystallinity (60.8%) occurred in the liquid nitrogen-quenched PA6/MMT film. The results show that the gamma -crystalline form is dominant in the rapidly cooled PA6/MMT.