Objective: To prospectively investigate the value of bone scintigraphy on determining the full extent of tumor involvement in jaw bones and to assess the presence of metastases. Methods: This study had local ethical committee ap-proval, and all patients gave written informed consent. Thirty seven consecutive patients with primary malignant tumor in jaw bones were recruited for the study. Bone scintigraphy was performed in all patients before surgery to measure the full extent of bony involvement, which was compared with histologic findings. Results: Whole body scan revealed one case with multiple bony metastases. Resection specimens of 36 bone neoplasms were pathologically analyzed to identify type and size of each tumor. The lengths of the tumor involvement in jaw bones defined by bone scintigraphy and pathology were 5.62 ± 1.58 cm, 4.48 ± 1.57 cm, respectively (P < 0.05). The tumor negative margins from removed specimens according to bone scintigraphy were pathologically confirmed. With histologic findings as the standard of reference, the accuracy of bone scintigraphy was 100% (36 of 36 patients) in determining the full extent of tumor involvement in jaw bones. Conclusion: Bone scintigraphy tends to offer specific guidelines in determining the appropriate extent of bone resection while entirely clearing the tumor cells and preserving functions whenever possible and in establishing the bony metastases.