The aims of this study were to investigate: (1) whether ratings of importance of, satisfaction with, and symptom/function of specific health-related quality-of-life (HRQoL) aspects are related, and (2) whether an importance–satisfaction discrepancy with regard to ratings of a specific HRQoL aspect is a valid indicator of distress. Eighty-three patients with endocrine gastrointestinal tumours completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and answered questions about importance of, satisfaction with, and symptom/function of 12 HRQoL aspects. The patients reported a relatively high HRQoL in terms of physical, emotional and social function. Most of the HRQoL aspects were considered as important for a good quality of life. High satisfaction was related to fewer symptoms and a better function. Patients who assigned a higher importance than satisfaction rating to an aspect reported a lower quality of life for the same aspect. The findings suggest that importance–satisfaction discrepancies are valid indicators of patient distress and illustrate the importance of asking patients not only about frequency and level of symptoms, but also about importance of and satisfaction with when assessing patient quality of life.