Summary: Corticosteroid-induced osteoporosis (CIOP) is currently undertreated. Systematic review of the literature revealed that the percentage of patients treated adequately is dependent on study quality. Therefore, it remains unknown whether adherence to the guidelines is really so poor. Five major quality criteria provide the standard for future studies on this scope. Introduction: It has recently been stated that the degree of prophylaxis of corticosteroid-induced osteoporosis (CIOP) is low and effort should be put into determining reasons for non-prescribing of preventive agents. The aim of this study was to identify: how many studies adequately audit the prevalent guideline; the longitudinal trends in prevention of CIOP; which patient groups appear to be most undertreated; and which intervention strategies are effective. Methods: We performed a comprehensive search of MEDLINE and systematically recorded the outcomes and quality of published studies, using five major criteria. Results: Twenty-four studies were included in the analysis. The quality of the included studies was poor (31%) or moderate (37%). There was a longitudinal increase in quality of the studies and percentage of prevention. Multivariable linear regression showed that the quality of the study was the only independent predictor of the prevention rate reported in the study. Conclusions: The results show undertreatment of CIOP might be due to insufficient quality of the studies rather than poor practice or failure to recognise the right patients. Future interventions should comply with five major quality criteria, and a multifaceted approach is required in order to make an impact on the underprescribing of CIOP prophylaxis.