BACKGROUND: Coeliac Disease (CD) is an increasingly common autoimmune condition, the treatment of which is a gluten-free diet (GFD). Previous studies fail to reach consensus of the impact this restrictive diet has on an individual's quality of life (QoL). Furthermore, how patient characteristics, such as demographic and educational background, may predict GFD adherence is poorly understood. We aimed to assess which factors had an impact on Qol in patients with CD. METHODS: Case-control postal survey (n=573). Biopsy-proven CD patients (n=225; mean disease duration 8yrs; range 0.5-52yrs; male 26%) and age and sex matched controls (n=348; male 36%) completed The Short-Form 36-Item (SF-36) QoL measure, The Hospital Anxiety & Depression Scale (HADS), GFD assessment, and demographic questionnaire. RESULTS: We found a high proportion of GFD adherence: 'Full Adherence' 65%, 'Partial Adherence' 31%, 'None Adherence' 4%, accompanied however, by 80% of patients reporting difficulty adhering to the GFD: 'Impossible' 5%, 'Mostly difficult' 14%, 'Sometimes difficult' 61%, 'No difficulty' 20%. Negligible differences in QoL scores were observed when comparing full versus partial/none GFD patients (P=>0.05), however, stepwise reductions in QoL and increasing likelihood of anxiety/depression were found in association with increasing degree of difficulty adhering to the GFD (P=<0.0001). Demographic assessment suggests that an affluent background and a university education promote greater GFD adherence. CONCLUSIONS: Most coeliac patients adhere to a GFD but encounter difficulty doing so (potentially influenced by social and educational background). The degree of GFD difficulty is associated with reductions in patient wellbeing and psychological distress that the dietician is critically placed to address.