A paradigm change is taking place in the diagnosis of osteoporosis - away from the overemphasis on bone mineral density (BMD) as the sole gauge of need for diagnosis and treatment towards a comprehensive risk assessment of all the components of increased bone fragility. The main risk factors, and thereby reasons for further diagnostics, are previous non-traumatic vertebral and non-vertebral fractures, long-term glucocorticoid therapy, low body weight, increased risk of fall, and disorders associated with an increased fracture risk. The indication for osteoporosis therapy is based on the individual fracture risk and should not be based purely on a single BMD value. Monitoring the effectiveness of osteoporosis treatment presents a challenge in everyday clinical practice. As an alternative to fracture incidence, surrogate markers (BMD, biochemical markers of bone turnover) can be used to assess effectiveness of treatment in the individual patient. Correct employment and interpretation of surrogate markers in osteoporosis therapy requires knowledge of pre-analytical and analytical factors which co-determine the measurement methods. The purpose of this overview is to examine the possibilities of clinical investigation, BMD measurement and determination of bone turnover markers for the evaluation of therapeutic response.