The effect of various solvents on the biodegradation of poly (-caprolactone) (PCL) was investigated at 45 °C using two different lipases: Novozyme 435 and Lipolase. The rate coefficients of polymer degradation and enzyme deactivation in acetone, toluene, benzene, benzyl alcohol, and acetone-water mixture were determined. Continuous distribution kinetics was proposed to model the deactivation of enzyme and polymer degradation and determine the rate coefficients. The effect of polarity and viscosity of the solvents on the degradation of the polymer was investigated. While the degradation rate decreased with viscosity, it increased with polarity for the solvents. The loss of enzymatic activity was less in Novozyme 435 compared to lipolase in non-aqueous solvents. Both the enzymes were sensitive to the amount of water present in the system and showed the maximum degradation of the polymers at an optimum value concentration of 8.7 wt.% of water in acetone. © 2002 Elsevier Science Ltd. All rights reserved.