Polycystic ovary syndrome (PCOS) is a far reaching condition that has a number of reproductive and general health implications. There has been much debate in recent years about the diagnosis and definition of PCOS and a plethora of studies assessing its management, ranging from the psychosocial aspects of the conditions, to the treatment of hyperandrogenism, anovulatory infertility, and the long-term metabolic and reproductive consequences. There has been a need to synthesise the evidence and produce an international consensus guideline for all aspects of the management of PCOS and this was achieved with the publication of the International evidence-based guideline for the assessment and management of polycystic ovary syndrome. The guideline is broadly categorised into 5 sections, which focus on diagnosis, holistic management and safe, effective fertility treatment. This article summarises the key points of the guidance and brings the management of PCOS up to date for the 21st century.