[en] Adherence to anti-osteoporosis medications is currently low and is associated with poor anti-fracture efficacy. This manuscript reviews the potential design of clinical studies that aim to demonstrate improved adherence, with new chemical entities to be used in the management of osteoporosis. Introduction Several medications have been unequivocally shown to decrease fracture rates in clinical trials. However, in real life settings, long-term persistence and compliance to anti-osteoporosis medication is poor, hence decreasing the clinical benefits for patients. Methods An extensive search of Medline from 1985 to 2006 retrieved all trials including the keywords osteoporosis, compliance, persistence or adherence followed by a critical appraisal of the data obtained through a consensus expert meeting. Results The impact of non-adherence on the clinical development of interventions is reviewed, so that clinicians, regulatory agencies and reimbursement agencies might be better informed of the problem, in order to stimulate the necessary research to document adherence. Conclusion Adherence to therapy is a major problem in the treatment of osteoporosis. Both patients and medication factors are involved. Adherence studies are an important aspect of outcomes studies, but study methodologies are not well developed at the moment and should be improved. Performing adherence studies will be stimulated when registration authorities accept the result of these studies and include the relevant information in Sect. 5.1 of the summary of product characteristics. Reimbursement authorities might also consider such studies as important information for decisions on reimbursement.