Background: The perception of self-discrepancies between the actual self and the ideal self has been defined as a cognitive risk factor for depression (Higgins, 1987). In this view, self-discrepancy monitoring (SDM) refers to the voluntary re-orientation of attention towards detecting discrepancies between ideal and actual selves, even in a positive situation. Aims: The goal of this study was to explore the impact of SDM on levels of mood in the face of positive stimuli. Method: Two clinical and two non-clinical samples were recruited from two different European countries (Italy and Romania). All participants were asked to focus on a past positive experience, and were then randomly allocated to one of two induction tasks. The experimental condition consisted of monitoring discrepancies between personal goals and the recalled positive experience, while the control condition consisted of observing what the participant was feeling. Results: The findings show that, after recalling a positive memory, SDM leads to a significant decrease in mood over a short period independent of the severity of depressive symptoms. This effect is partially mediated by the concurrent change in levels of brooding. Conclusions: Self-discrepancy monitoring in response to positive stimuli tends to lower current mood independent of the initial level of depressive symptoms, and seems to be a global trigger of emotional distress that does not refer only to a depressed cognitive style.