This paper addresses the specific mechanical properties from difference microstructures of syntactic foam. In this study we assessed the specific tensile, compressive and flexure strength and modulus for syntactic foam containing various volume fractions of hollow microspheres. Three different types of hollow microspheres were studied. Preliminary tensile and flexure results showed a decreasing trend for the specific strength of syntactic foam with increasing filler content. Interestingly, the specific tensile and flexure modulus elicited a different trend for each type of filler. Especially the increase in specific Young's modulus for the K46 glass microspheres was noteworthy since this trend has not been reported before. Compression tests showed the specific compressive strength decreased with increasing filler content. The specific compressive modulus, however, increased with increasing filler content.