OBJECTIVE: There is increasing interest in the impact of endometriosis on body image, however, there is minimal understanding of the presence and nature of disordered eating. As body image dissatisfaction is elevated in this population and a risk factor for eating disorders, it is likely that disordered eating is also elevated which has important clinical implications for prevention and intervention. The current study aimed to explore the relationships between endometriosis, body image flexibility, eating disorder psychopathology, negative affect, and self-criticism using a mixed-methods design. METHOD: People (n = 179) with endometriosis, over the age of 18 years, and living in Australia were recruited using social media. Quantitative measures included the Body Image Acceptance and Action Questionnaire, Eating Disorder Examination Questionnaire 7-item Short Form, Depression Anxiety and Stress Scales, and the Inadequate Self subscale of the Forms of Self-Criticising/Attacking and Self-Reassuring Scale. Participants were also asked two open-ended questions that enabled reflexive thematic analysis of the impact endometriosis has on body image and eating, using Braun and Clarke's six phase process. RESULTS: Participants were mostly female, heterosexual, White, and had a mean age of 30. The sample demonstrated high levels of eating disorder psychopathology, negative affect, and self-criticism, and low body image flexibility. Thematic analysis yielded three main themes, that were highly consistent with quantitative findings: Body disappointment, Food as an enemy, and Stolen identity and joy. CONCLUSIONS: This study highlights the need for prevention and intervention efforts focused on reducing eating disorder psychopathology and body image concerns experienced by individuals with endometriosis.