Segmental bone defects are challenging clinical problems, and current surgical solutions are associated with high complication rates. In oncologic reconstructive surgery, bone healing will occur coincidently with the administration of chemotherapy to treat the underlying disease. Effective methods of graft modification or bone graft alternatives can be of great help clinically. A series of osteoinductive proteins (bone morphogenetic proteins or BMPs) has been described and shown to enhance bone formation in animal models. This study was designed to evaluate the effect of chemotherapy on bone healing enhanced by rhBMP-2. We used a critical-sized bone-defect rabbit model. Histological and radiological analysis showed that chemotherapy affects both the quantity and the quality of the bone enhanced by the addition of rhBMP-2. These results suggest that the effect of chemotherapy on bone formation could be related to inhibition in a specific pathway stimulated by the rhBMP-2.