It has been apparent for some time that utilisation of health services is more influenced by how people feel than by their 'objective' symptoms. Research has also shown that compliance with treatment regimens is dependent on the impact of that treatment on the patient's well-being. Such findings highlight the need to assess the patient's view of his or her progress through the health care system. This has led to a growing interest in quality of life assessment and, in particular, to the impact of illness and its treatment on the quality of life of the patient. Perhaps surprisingly, interest in quality of life measures for outcome assessment in Psychiatry has been slower to develop than in other specialties. While a number of clinician- and patient-completed measures of the severity of depressive symptoms exist, no measure of the quality of life of depressed patients is available. This paper describes the development and testing of the Quality of Life in Depression Scale (QLDS), a new measure designed to fill this gap. The theoretical basis for the instrument is that life gains its quality from the ability and capacity of the individual to satisfy his or her needs. The items included in the QLDS were derived from 30 qualitative interviews with depressed or recently recovered patients. Further interviews were held with depressed patients to establish the face and content validity of the instrument. Respondents had little trouble completing the questionnaire and found the content to be relevant to their experience of depression. The QLDS represents an important advance in our ability to understand the impact of depression on quality of life.