Lattice block structures (LBS) - also called lattice-truss structures, truss-core sandwiches, and cellular lattices - are three-dimensional-periodic reticulated materials that derive their outstanding mechanical performance from a high-symmetry arrangement of internal trusses connected at nodes.  They are innovations that provide tremendous opportunities for weight and cost reduction in future aerospace systems, both commercial and military.  In this presentation, the structural and mechanical characterization of individual Ti-6Al-4V struts and complete Ti-6Al-4V LBS panels produced by investment casting are reported.  Testing in compression, bending, and impact show that high strength, ductility and energy absorption are achieved for both individual struts and full panels, despite the difficulties of casting such fine struts from a highly reactive liquid titanium alloy.  The experimental compressive stress-strain behavior of the LBS panels will be compared to finite-element modeling predictions.  This work was supported by NASA-Glenn Research Center.