This study aims at evaluating bone growth in critical-sized femoral defects of rats filled with macro micro porous biphasic calcium phosphate ceramic (MBCP) cylinders surrounded or not by a resorbable collagen membrane. Femoral defects left empty (control) exhibited partial bone ingrowths after 3 and 6 weeks and were completely healed at 12 weeks. The defects filled with the collagen membranes appeared partially healed suggesting that the membranes constraint bone ingrowth. Bone formation occurred around the collagen membrane which partially degraded over time. In the MBCP/membrane group, bone has grown inside the macro pores of the MBCP cylinders. Bone ingrowth was more rapid and abundant in the defects filled with MBCP alone. The combination MBCP/collagen membrane may be beneficial for the reconstruction of large bone defects without using repetitive surgeries and autologous bone grafting.