The results obtained in Part I relative to the enzyme-catalyzed hydrolysis of poly(1,2-propanediyl fumarate) are applied to the hydrolysis of the networks prepared from this polyester. The weight loss of polyester samples after 14 days of hydrolysis was correlated to the degree of crosslinking (a) determined by differential scanning calorimetry (DSC). In this work, it was shown that the enzyme-catalyzed hydrolysis rapidly takes place on the uncrosslinked polyester chains only, whereas the chemical hydrolysis affected both free and crosslinked chains. The initial hydrolysis rate of the chemical process does not depend on a or on the nature of the chains (free or crosslinked) but it is lower than that of the enzymatic process.