Background: Osteoradionecrosis of the jaw is a major side-effect of radiotherapy used in the treatment of squamous cell carcinomas of the upper aerodigestive tract. The standard reconstruction procedure is a free flap transfer of autogenous bone. A new approach using a tissue engineering strategy has shown that total bone marrow (TBM) associated with biphasic calcium phosphate (BCP) is the best combination for bone regeneration in an irradiated area. Recently, the stromal vascular fraction from adipose tissue (SVF) was described as an alternative to TBM for promoting new bone formation. The aim of this study was to identify the capacity of a freshly isolated SVF to induce new bone formation in an irradiated area. Methods: Four weeks after irradiation of the hind limbs of 15 rats, bone defects were created and filled with either SVF or TBM with and without BCP. Results: Three weeks after the implantations, analysis showed that the BCPeTBM mixture improved new bone formation after radiation (p < 0.05). The BCPeSVF association induced significant neoangiogenesis but failed to enhance new bone formation. Conclusion: The BCPeSVF mixture was insufficient to enhance new bone formation in the irradiated area, suggesting that the role of the environment might be crucial for ossification.