We describe a patient with progressive metastatic bone disease involving a pedicle of the lumbar spine, in whom serial bone scans were performed. Initially, increased radiotracer accumulation was evident, corresponding to an osteoblastic lesion found on CT. Later, radiotracer uptake appeared to be normal, while an expansile tumor causing osteolytic change was noted on CT. We suggest that false-negative bone scan can occur in the natural process of progressive bone metastasis.