Research in biomedical materials has received increasing attention recently. In particular, porous titanium alloys are attractive due to its unique physical, mechanical, and biocompatibility properties. The aim of this work is to analyis the microstructure of the developed porous b titanium alloy produced by powder metallurgy based on the expansion of pressurized argon bubbles technique. This fabrication procedure involved; blending of elemental powder, i.e., Ti, Nb, Ta, Zr, pressurized gas infusions, densification using HIP (Hot Isostatic Press) and pores expansion at 1350oC for 10 hours in vacuum followed by furnace cooling. Foamed specimens were characterized for microstructure and microhardness by optical microscopy and scanning electron microscopy and Vickers indentation, respectively. Porosity levels of the porous titanium alloy of 45% have been achieved with pore sizes in the range of 18.2-190 mm. The porosity level increased with increased argon backfill pressure. Microstructures of the porous titanium alloys exhibited the presence of a-phase and a platelets within the b-phase matrix. Homogenization of the alloy was complete indicating that the phases grow along with pore expansion. The hardness values of the prominent phase comparable to the range used in parts produced by conventional techniques.