The feasibility, face validity and repeatability of a self-complete questionnaire to assess patients' attitudes and beliefs about asthma was evaluated in 45 adult patients attending a hospital asthma clinic. The questionnaire consisted of 40 statements with which the patient agreed or disagreed by placing an 'X' along a visual analogue line. Patients completed questionnaires at their clinic consultation and then were interviewed to ascertain whether questionnaire responses agreed with a verbal description of their attitudes and beliefs. Repeatability was assessed by having patients complete an identical questionnaire four weeks after their interview. The questionnaire responses showed excellent agreement with interview findings, suggesting that face validity was good. Repeatability also appeared satisfactory in that agreement between responses on the first and second questionnaires was significant for 31 of the 40 items. Many patients (22%) incorrectly used the analogue line response scale making feasibility unacceptably low. However, subsequent studies showed this problem could be overcome by the use of a four-point Likert response scale. These findings suggest that this questionnaire is a satisfactory instrument for assessing patients' attitudes and beliefs about asthma. Its face validity appeared good and, with certain modifications, it was both feasible and repeatable.