AbstractCrystallization kinetics of poly(e‐caprolactone) from the blends of poly(e‐caprolactone (PCL) and poly(vinyl chloride) (PVC) were investigated. The isothermal spherulitic growth rates were measured with an optical microscope. Linear growth rates were obtained for all samples at temperatures between 20° and 35°C. The introduction of PVC into PCL resulted in a reduction in spherulitic growth rate. The overall crystallization rates were measured with a density gradient column. The Avrami equation was employed to analyze the isothermal crystallization kinetics. It was found that the value of Avrami constantkdecreases markedly with increasing PVC concentration. However, the Avrami constantnhas a value in the neighborhood of 3, almost independent of the composition. In light of these results, it is suggested that, for these blends, the crystallization proceeds by heterogeneous nucleation, followed by a three‐dimensional