Aim To systematically review the evidence for a relationship between sex hormones and structural changes in osteoarthritis (OA). Methods Electronic searches of MEDLINE were performed in Novembera??December 2010 and in February 2011 for studies of sex hormones and OA that met a predefined set of criteria. Both controlled trials and observational studies were eligible for inclusion. Two independent reviewers extracted the data and assessed the methodological quality of the included studies. Due to the heterogeneity of the studies, we were unable to perform a best evidence synthesis. However we have provided summaries for each section.