In the evaluation of therapeutic measures it is important to consider the consequences of the proposed treatment on the subjective quality of health and the subjective quality of life. Since no adequate instrument existed to provide such assessments, a short, theoretically based questionnaire was developed and psychometrically tested. The construction phase was based on data of 104 adults with haemato-oncological diseases, leading to the design of a questionnaire which was tested using data of a further 292 patients. The validity of the "questionnaire for attitudes towards quality of health and quality of life" was assessed by comparing it with physicians' ratings and by correlation with the results of an extensive questionnaire. The reliability was satisfactory; the questionnaire met with high acceptance by patients, physicians and health care personnel. It complies with the requirements of clinical trials where the objective is to measure quality of health and quality of life.