Aims The aim of this official guideline published and coordinated by the German Society of Gynaecology and Obstetrics (DGGG) in cooperation with the Austrian Society for Gynaecology and Obstetrics (OEGGG) and the Swiss Society for Gynaecology and Obstetrics (SGGG) was to provide consensus-based recommendations for the diagnosis and treatment of endometriosis based on an evaluation of the relevant literature. Methods This S2k guideline represents the structured consensus of a representative panel of experts with different professional backgrounds commissioned by the Guideline Committee of the DGGG, OEGGG and SGGG. Recommendations Recommendations on the epidemiology, aetiology, classification, symptomatology, diagnosis and treatment of endometriosis are given and special situations are discussed.