Polypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepd. via melt intercalation using dodecylsulfate anion modified LDH and maleated PP as compatibilizing agent. Evidently the interlayer anions in LDH galleries react with maleic anhydride groups of PP-g-MA and lead to a finer dispersion of individual LDH layers in the PP matrix. The nanostructure was characterized by XRD and TEM; the examns. confirmed the nanocomposite formation with exfoliated/intercalated layered double hydroxides well distributed in the PP matrix. The nonisothermal crystn. behavior of resulting nanocomposites was extensively studied using differential scanning calorimetry (DSC) technique at various cooling rates. In nonisothermal crystn. kinetics, the Ozawa approach failed to describe the crystn. behavior of nanocomposites, whereas the Avrami anal. and Jeziorny method well define the crystn. behavior of PP/LDH nanocomposite. Combined Avrami and Ozawa anal. (Liu model) also found useful. The results revealed that very small amts. of LDH (1%) could accelerate the crystn. process relative to the pure PP and increase in the crystn. rates was attributed to the nucleating effect of the nanoparticles. Polarized optical microscopy (POM) observations also support the DSC results. The effective crystn. activation energy was estd. as a function of the relative degree of crystallinity using the isoconversional anal. Overall, results indicated that the LDH particles in nanometer size might act as nucleating agent and distinctly change the type of nucleation, growth and geometry of PP crystals.