In our previous research, we had successfully developed antimicrobial PCL/nanoclay nanocomposite films with enhanced mechanical and water vapor barrier properties for food packaging field. Now, in this present work, we complete our study by investigating the thermal stability and decomposition kinetics of these materials using thermogravimetry technique (TGA). The TGA results revealed that the incorporation of 3% of organoclay in the PCL matrix reduced the thermal stability of PCL nanocomposite films. In addition, the decomposition kinetic study showed that the apparent activation energies Ea of the thermal degradation of the PCL nanocomposites are lower compared to those calculated for pristine PCL, confirming the catalytic effect of the organoclay upon the PCL decomposition. The master plots of g(alpha) function showed a similar thermal degradation mechanism of PCL and its PCL nanocomposites. All the studied samples followed Avrami-Erofeev, m = 1.5 model. Also, the thermodynamic parameters such as Delta H-#, Delta S (#) and Delta G (#) were calculated and discussed.