Low health-related quality of life among morbidly obese subjects is well-known. However, the relationship may not be simple. We aim to examine the association between pre-operative expectations and health-related quality of life and long-term changes in health-related quality of life after gastric banding. The questionnaires were answered twice: before and five years after gastric banding. Short Form-36 assessed health-related quality of life. Obesity specific questions were used to assess the subjects' attribution of impairment to morbid obesity and their expectations to changes as a result of weight loss. The subjects attribute morbid obesity as a major reason for their impairments in state of health, physical activity, pain and work capacity. As a result of weight loss, the subjects expect improvements even within fields which they did not consider to be impaired due to morbid obesity. We found an inverse association between high expectations and mental component summary score at baseline. At follow-up having expectations fully fulfilled was associated with a higher mental component summary score than having expectations fulfilled only to a fair extension and not having expectations fulfilled. Physical component summary was statistically significant improved at follow-up Morbidly obese subjects' attributions of low general well-being combined with their expectations may be a central part of understanding the mechanisms involved in the association between morbid obesity and low health-related quality of life. Furthermore the impact of morbid obesity on health-related quality of life may be reduced if healthprofessionals bridge the gap between morbidly obese subjects' expectations and their experience.