An industrial scale injection molding machine is used to prepare fly ash cenosphere reinforced high density polyethylene (HDPE) syntactic foams. Thermosetting matrix foams with glass microspheres are being used in marine and aerospace applications owing to higher specific properties. Thermoplastic matrix syntactic foams have not been studied extensively despite interest in them for lightweight underwater vehicle structures and consumer products. Syntactic foams are fabricated with 20 and 40% cenospheres by weight. The studies on the manufacturing process suggest that a small percentage of cenospheres fracture in syntactic foams containing up to 40 wt.% cenospheres. Incorporation of particles, which are inexpensive, helps in fabricating low cost syntactic foams. Quasi-static compression tests are conducted at 10-4, 10-3 and 10-2 s-1 strain rates. The compressive strength of syntactic foams is higher than that of HDPE resin at the same strain rate due to the incorporation of ceramic particles. Yield strength shows an increasing trend with strain rate.