Medium-chain-length poly(hydroxyalkanoates) (mcl-PHAs) were synthesized from coconut oil (PHA-C), tallow (PHA-T), and soybean oil (PHA-S) by bacterial fermentation using Pseudomonas resinovorans as the producer strain. Films were solution-cast and subjected to 50 kGy of γ-irradiation. This resulted in crosslink formation based on the number of olefinic groups present in the polymer side-chains. In each case, radiation improved the tensile strength (104% and 63%), percent elongation (49% and 13%), and Young's modulus (30% and 76%) of PHA-C and PHA-T films, respectively. The greatest effect was on PHA-S, which was converted from an amorphous, liquid-like material to a solid elastomeric film.