In this study we evaluated different biopsy techniques for the quantitative study of bone histology. Bone biopsies were done using an electric drill and a Jamshidi needle after tetracycline double-labeling in patients with renal bone disease, osteoporosis, or Paget's disease. Bone slides were stained with Masson-Goldner stain and evaluated for quantitative static and dynamic parameters of bone structure, formation, and resorption. Statistical evaluation of the differences and correlations between histomorphometric parameters obtained from slides of bone samples thirty-five millimeters long and five or three millimeters in diameter revealed that three-millimeter samples were sufficient for qualitative diagnosis but were not optimum for the quantitative evaluation of cellular parameters of resorption and dynamic parameters of formation. A useful compromise might be the use of a four-millimeter specimen obtained with the less invasive technique that hitherto has been employed only for smaller samples. Clinical Relevance: Several bone-biopsy techniques are available that provide bone samples of different sizes. Knowledge of the smallest sample size that is sufficient for qualitative and quantitative diagnosis of metabolic bone diseases will help the physician to select the least-invasive techniques without losing relevant information.