Hydrolytic degradation of poly(1,2-propanediyl fumarate) was carried out in mild experimental conditions using Chromobacterium viscosum lipase as catalyst. The influence of pH, temperature, enzyme concentration, and enzyme inactivation on the initial hydrolysis rate has been analyzed. Enzymatic and chemical processes were compared. This study is an introduction to the enzyme-catalyzed hydrolysis of networks based on unsaturated polyesters.