The effect of mood on memory was studied under natural conditions in 2 field quasi-experiments. In both, Ss in happy moods recalled autobiographical memories that were more negative than were memories recalled by subjects in bad moods, a phenomenon termed mood incongruent recall. Three subsequent laboratory experiments are reported that suggest that mood incongruent recall is a reliable phenomenon, occurring when subjects are unaware that their moods are relevant to the experiment. Mood incongruent recall is hypothesized to be related to mood regulation. The implications of these findings for the relation between mood and memory, for mood congruent recall, for laboratory mood inductions, and for self-regulation of mood and depression are discussed.