Background: The McGill Quality of Life Questionnaire has been widely used with people with life-threatening illnesses without modification since its publication in 1996. With use, areas for improvement have emerged; therefore, various minor modifications were tested over time. Aim: To revise the McGill Quality of Life Questionnaire (McGill Quality of Life Questionnaire-Revised) while maintaining or improving its psychometric properties and length, keeping it as close as possible to the McGill Quality of Life Questionnaire to enable reasonable comparison with existing McGill Quality of Life Questionnaire literature. Design: Data sets from eight studies were used (four studies originally used to develop the McGill Quality of Life Questionnaire, two to develop new McGill Quality of Life Questionnaire versions, and two with unrelated purposes). The McGill Quality of Life Questionnaire-Revised was developed using analyses of measurement invariance, confirmatory factor analysis, and calculation of correlations with the McGill Quality of Life Questionnaire's global quality of life item. Setting/Participants: Data were from 1702 people with life-threatening illnesses recruited from acute and palliative care units, palliative home care services, and oncology and HIV/AIDS outpatient clinics. Results: The McGill Quality of Life Questionnaire-Revised consists of 14 items (plus the global quality of life item). A new Physical subscale was created combining physical symptoms and physical well-being and a new item on physical functioning. The Existential subscale was reduced to four items. The revised Support subscale, renamed Social, focuses more on relationships. The Psychological subscale remains unchanged. Confirmatory factor analysis results provide support for the measurement structure of the McGill Quality of Life Questionnaire-Revised. The overall scale has good internal consistency reliability (=0.94). Conclusion: The McGill Quality of Life Questionnaire-Revised improves on and can replace the McGill Quality of Life Questionnaire since it contains improved wording, a somewhat expanded repertoire of concepts with fewer items, and a single subscale for the physical domain, while retaining good psychometric properties.