To provide a contemporary approach to the understanding of the impact and methods for the diagnosis of endometriosis in Canada. Individuals, families, communities, health care providers, and health care administrators who are affected by, care for patients with, or manage delivery of services for endometriosis. The diagnosis of endometriosis is facilitated by a detailed history, examination, and imaging tests with providers who are experienced in endometriosis care. Surgical evaluation with pathology confirms a diagnosis of endometriosis; however, it is not required for those whose diagnosis was confirmed with imaging. There is a need to address earlier recognition of endometriosis to facilitate timely access to care and support. Education directed at the public, affected individuals and families, health care providers, and health care administrators are essential to reduce delays in diagnosis and treatment. Increased awareness and education about the impact and approach to diagnosis may support timely access to care for patients and families affected by endometriosis. Earlier and appropriate care may support a reduced health care system burden; however, improved clinical evaluation may require initial investments. Each section was reviewed with a unique search strategy representative of the evidence available in the literature related to the area of focus. The literature searches for each section of this guideline are listed in Appendix A and include information from published systematic reviews described in the text. The recommendations were developed following two rounds of review by a national expert panel through an iterative 2-year consensus process. Further details on the process are shared in Appendix B. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See Appendix C (Table C1 for definitions and Table C2 for interpretations of strong and conditional recommendations). This guideline is intended to support health care providers and policymakers involved in the care of those impacted by endometriosis and the systems required to support them.