The importance of positive mood for health and well-being is a truism. However, we still lack clear understanding of the nature and range of modulatory effects created by positive mood on cognition in humans. Here, we briefly review two recent research lines that have attempted to address this question systematically. Specifically, research on attention has explored the boundaries of the so-called broadening of attention with positive mood. Likewise, effects of positive mood on error monitoring have been scrutinized lately. The new empirical findings gathered in these two separate research domains concur on the assumption that positive mood is not merely adding noise to cognition. Instead, this mood state seems to provide the organism with meaningful (internal) information, which allows for timely and flexible exploration of new opportunities in the (external) environment and alters the motivational significance of negative events, such as response errors, in a rather flexible way. As such, these new findings provide information about the existence of complex interaction effects between positive mood and cognition and may help, in turn, to better appraise the actual role and function of this protective mood state for health and cognition.