OBJECTIVES: Healthcare payers are interested in funding bariatric surgery because it resolves a range of obesity-related health problems. However, following weight loss, many patients are left with unsightly excesses of skin and require body-contouring surgery. Our team has developed a new PRO instrument (i.e., the BODY-Q) to measure satisfaction and quality of life of bariatric and body-contouring surgery patients. Unlike existing PRO instruments, the BODY-Q is composed of scales that measure appearance-related concerns, which is an important reason why patients seek treatment. The BODY-Q also stands apart as it the only PRO instrument designed to measure change in patients concerns throughout the entire weight loss journey. METHODS: We followed international guidelines for the development of a PRO instrument. This abstract presents Phase I results, i.e., qualitative phase. Patient stories were used to develop a conceptual framework covering the key concerns of patients, and to develop a set of preliminary items. Items were grouped into clinically meaningful scales and instructions and four-point response options were developed. The scales were refined by obtaining feedback from a sample of surgical experts and patients.  RESULTS: From 59 patient interviews, we developed a conceptual framework. Over 3,500 preliminary items were developed and used to inform the following 17 independently functioning scales: (1) appearance scales measuring the body, abdomen, upper arms, buttocks, inner thighs, hip and outer thighs, skin and scars; (2) quality of life scales measuring body image, sexual, psychological and social wellbeing, physical function and symptoms; and (3) process of care scales measuring satisfaction with information, doctor and office staff.  CONCLUSIONS: Phase II involves a multi-centered field-test in Canada and the USA. Rasch Measurement Theory analysis will be used to determine which items to retain in each scale based on their performance against a standard set of psychometric criteria.