Additive manufacturing techniques have made it possible to create lighter and stronger lattice structures with intricate repeating geometric patterns which can be utilized for various industrial applications. Although several studies have reported on the effects of lattices with varying geometry on mechanical properties, fewer studies have investigated the effects of post-processing parameters on mechanical properties of these lattices. As such, this study investigates the effects of solid fraction of octet truss-based lattices and the effect of heat treatment on the mechanical properties of 3D printed octet truss lattices. Experimental findings revealed that Young’s Modulus and strength of lattices were enhanced upon heat treatment where tensile strength and stiffness of lattices with 40 % solid fraction improved by 20.55 % and 29.11 % respectively. Besides, it was found that the lattices without and with heat treatment obeyed the Ashby’s classic scaling law reasonably well for both modulus-density and strength-density relationship.