Our laboratory has been developing a particulate composite material as a temporary replacement for trabecular bone. The material is degradable in physiologic fluids, and uses starting materials that the body can metabolize and excrete. This study investigates the influence of the molecular weight of one component, a linear polyester, on the mechanical strength of the composite material. The compressive strength and modulus increase from “low” to “medium” molecular weight, but do not increase further from “medium” to “high” molecular weight. Low, medium, and high are relative to the highest molecular weight attainable with the current reaction scheme, which is a number average molecular weight (Mn) of 2,038 and a weight average molecular weight (Mw) of 11,916.