Objective: To gain insight into patients’ understanding of endometriosis, utilised sources of information on endometriosis, and perceptions of available treatment options. Design: Observational cross-sectional study. Setting: Data were collected from an outpatient specialist endometriosis clinic within a tertiary hospital. Participants: New patients referred with symptoms suggestive of endometriosis. Methods: A paper based questionnaire was completed by new patients on their first presentation to the clinic. Main outcome measures: Patient understanding of symptoms and causes of endometriosis, types and expectations of treatment, and sources of information utilised by patients in researching endometriosis. Results: Approximately half of all included patients were unsure of the aetiology of endometriosis. Patients who relied on information from specialist gynaecologists were more optimistic about the outcome of surgical treatment, while those who relied on general practitioners were more optimistic about the outcome of medical treatment, when compared to those who sought information from online sources. Conclusions: Endometriosis is a chronic and debilitating condition, yet there is limited data available regarding both the sources of information that patients’ access, and their perceptions of the disease. Given the high proportion of patients in our study who lacked knowledge of endometriosis, and the negative correlation between the use of social media for information and perception of treatment, there is a clear need for improved access to evidence-based resources for patient education. Funding: None received Keywords: Endometriosis, laparoscopy, social media, patient education