Three-dimensional glass fabric composites were fabricated using unsaturated polyester resin and fabrics of different vertical fiber lengths. The compressive properties of the composites were investigated by flat compression tests. Also interlaminar shear strength (ILSS) was characterized by short-beam test to the evaluate the interfacial adhesion between the fibers and the matrix of the composites. The changes in vertical fiber length of the composites greatly influenced the compressive and interlaminar shear properties, as opposed to those of classical honeycomb sandwich structures (nomex, alumina, kraft paper). This seems to be a consequence of the buckling phenomenon of the 3D hollow structures formed during the resin matrix curing.