The model proposed by Ziabicki [1] [2] for non-isothermal crystallization kinetics was adopted in this work, to describe the crystallization kinetics of a commercial iPP under a very wide range of conditions (i.e. isothermal, slow-cooling rate and high-cooling rate (up to 200 degreesC/s) from the melt). A modification of the model was required in order to achieve a good agreement between model predictions and the whole set of experimental data.