The second edition of Dr. Sydney Lou Bonnick’s text Bone Densitometry in Clinical Practice is an expansion of her highly regarded first edition, which has provided the bone densitometry community with simply the best, most accurate, and most precisely written resource in our field. Dr. Bonnick has applied her very careful and exact scientific approaches to expand and improve on her widely regarded initial text. In addition to the chapters in the first edition on the science of bone densitometry and its clinical appli- tion, this text has new chapters and a CD-ROM that come at a very critical time in our field. The clinical use of bone densitometry is increasing exponentially as more professional societies have endorsements and guidelines on the application of bone densitometry in the assessment and management of osteoporosis. The recent endorsement of population screening by the US Preventive Services Task Force (USPSTF) has now provided g- ernmental validation to this technology, whose proper use Dr. Bonnick has pioneered. In a new chapter, Dr. Bonnick compares the similarities and differences in the recent gui- lines from the USPSTF and the National Osteoporosis Foundation, American Assoc- tion of Clinical Endocrinologists, American College of Obstetrics and Gynecology, and the North American Menopause Society.