This study was designed to evaluate the biocompatibility and potential in vivo toxicity of the degradation products of three novel magnesium alloys Mg-3Y (W3), Mg-4Y-4Li (LW44) (extruded and ECAP forms) and Mg-0,5Ca-1,0Zn-0Mn in a rabbit model and compared them with well-known commercial magnesium alloy Mg-Y-RE-Zr (WE43). The screws and pins of these different materials were implanted into the New Zealand White rabbits' femoral shafts (2 screws and 2 pins in each animal). Blood samples were collected from ear arteries at the day of implantation (day 0) and 6, 12, 18 and 24 weeks post-surgically. Complete blood counts and biochemical parameters (liver enzymes, renal parameters, Ca, Mg, Zn and Li) were determined. The tissue samples extracted from the liver, spleen, and kidney were assessed for histological analysis after euthanization. No significant changes in blood cell count, serum levels of metal ions released from alloys, or any changes in liver enzymes and renal function parameters were detected. No systemic inflammatory reactions were observed in any of the animals. In addition, no changes in organ morphology after exposure to all types of alloys after 24 weeks of exposure were observed.