Efforts to prevent complications of diabetes often overlook the impact of the condition and its treatment on current quality of life (QoL). The Diabetes Treatment Satisfaction Questionnaire (DTSQ) has proved valuable for understanding and measuring patients' treatment satisfaction in assessments of new treatments and strategies. For example, the DTSQ has demonstrated improved patient satisfaction with fast-acting insulin lispro versus standard soluble insulin and with long-acting insulin glargine versus NPH insulin. However, improvements in treatment satisfaction are often inferred to be improvements in overall QoL without recognizing the limited scope of the satisfaction measure. It is necessary to evaluate not only satisfaction with treatment per se but also the impact of diabetes and its treatment on a broad range of life domains in order to assess the impact on QoL. The Audit of Diabetes-Dependent Quality of Life (ADDQoL) measure is a diabetes-specific instrument that assesses the impact of diabetes on 18 life domains. Use of the ADDQoL with people with type 1 or type 2 diabetes has shown, on average, almost universally negative impact of diabetes on all domains. Significant differences have also been shown in the magnitude of effect between insulin-treated and non-insulin-treated patients and patients with and without complications. The negative impact of diabetes on QoL has been observed despite high levels of treatment satisfaction (as measured by the DTSQ). The greatest negative impact was observed for the domain ‘Freedom to eat as I wish’, indicating the strong influence of dietary restrictions on QoL. Studies to assess the outcomes of treatment approaches designed to improve dietary flexibility are under way. Copyright © 2002 John Wiley & Sons, Ltd.