Identifying daily influences on subjective well-being can be helpful in understanding the burden of depression. This study used experience sampling methodology (ESM) to examine the contribution of mood states, physical complaints and enjoyment of activities to a momentary measure of quality of life (mQoL), assessed by responses to the question 'In general, how is it going with you right now?' Sixty-three depressed and 22 healthy control subjects completed ESM self-reports during daily activities, 10 times per day for 6 days. In comparison to control subjects, depressed subjects had lower levels of mQoL, positive mood, and enjoyment of activity, higher negative mood, and more frequent and severe complaints. Depressed subjects were more likely than control subjects to be doing nothing and less likely to be engaged in work. Multilevel regression analysis showed that positive mood and enjoyment of the current activity were associated with higher mQoL, whereas negative mood and complaints were associated with lower mQoL. In depressed subjects, mQoL was more variable over time than in control subjects. In contrast to the ESM results, only negative mood and depression were significant predictors of global measures of QoL. We conclude that QoL has important situational determinants that can in part explain the impact of depression on daily functioning and well-being. Copyright (C) 1999 Elsevier Science Ireland Ltd.