AIMS To evaluate whether health-related quality of life in adult coeliac disease is related to: 1) adhesion to gluten-free diet; 2) manifestation of clinical features; and 3) associated diseases. PATIENTS AND METHODS A total of 68 coeliac patients (54 female and 14 male) aged between 18 and 74 years, on gluten-free diet for at least two years were studied. The subjective health status was measured by means of the Short Form 36 Health Survey. A series of 136 subjects, matched according to sex, age and ethnic group, were evaluated as control group. RESULTS Patients obtained worse scores with respect to healthy controls at all domains of Short Form 36 Health Survey (p<0.05); compliers showed better results than non-compliers. The lowest scores were obtained in patients with more than six symptoms, mostly in non-compliers, the highest in compliers with less than six symptoms. Patients with two or more associated diseases presented significantly worse scores than patients with only one associated disease. CONCLUSIONS The importance of gluten-free diet in clinical management of coeliac disease is confirmed by results of the present study; moreover, the results seem to indicate that a complex interplay of factors should be taken into account in evaluating health-related quality of life in adult coeliac disease. Accordingly, our data show that health-related quality of life of coeliac patients is impaired not only by poor compliance but also by different negative factors such as severity of illness (in terms of number of symptoms) at diagnosis and comorbidity.