The microstructure and tensile properties of a metal injection molding 0.23%C Co-Cr-Mo alloy (F75 alloy) were investigated. The as-sintered microstructure contains a significant amount of carbides, and is modified by solution annealing, the main effect being to reduce the amount of carbides. Ductility and ultimate tensile strength increase significantly, but yield strength decreases with solution annealing. Aging causes both intragranular and intergranular precipitation, which increases hardness and yield strength but decreases ductility excessively. In both as-sintered and solution-annealed conditions, the material displays noticeable work hardenability. By sintering at 1300 A degrees C and solution annealing at 1220 A degrees C, 440 MPa yield strength and 25% elongation at fracture are obtained.