Percutaneous bone biopsy has become an accepted means for tissue diagnosis in indeterminate metastatic disease, whereas needle biopsy for the evaluation of primary skeletal neoplasms is controversial. Needle biopsies are also of value in the diagnosis of inflammatory lesions and eosinophilic granuloma. The diagnostic accuracy of this procedure ranges from 50 to 94% in malignant disease, but is less favorable in benign disease. The low complication rate of about 0.2% makes the percutaneous approach an attractive alternative to surgical biopsy.