In this paper economic evaluation of osteoporosis prevention is discussed. So far economic evaluation in this area has been limited to cost-effectiveness analysis. Four cost-effectiveness analyses of osteoporosis prevention are reviewed. It is noted that the major problem with these studies is the lack of reliable and valid data to base the cost-effectiveness analyses on, which precludes clear-cut conclusions about the cost-effectiveness of osteoporosis prevention. The studies, however, form a basis for future cost-effectiveness analyses in this field and as new data become available it should be possible to improve the accuracy and precision of the analyses. Due to the methodological problems of cost-effectiveness analysis and the decision-maker approach to economic evaluation, it is also argued that the contingent valuation (CV) method of measuring willingness to pay should be tested in this area. The CV method can be used both to value an actual treatment and the outcome of that treatment and the resulting amount can be compared with the costs (including the costs of externalities) to carry out cost-benefit analysis. It is concluded that a lot of work remains to be done in this area before economic evaluations can give a real contribution to policy, but such work may well be worthwhile due to the importance of this public health problem.