Reaction injection moulding of blend samples of poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) (PHBV) and poly-epsilon-caprolactone (PCL) has been performed in the presence of peroxide. The blends are compared to mechanical PHBV/PCL blends obtained in the absence of peroxides. Differences in chemical-physical and mechanical properties are interpreted on the basis of intergrafted species present in the peroxide-treated blends. The obtained blends are proposed as versatile materials for applications for bioresorbable prostheses.