Individuals can apply different processing strategies to deal with situations they encounter. One central question in social-cognition research refers to the factors that determine reliance on different processing strategies. Parting from a functional perspective, which holds that processing strategies need to be adjusted to the requirements of the situation, we argue that individuals' mood carries information about the benign versus problematic nature of the situation and thus that mood can regulate cognitive processing. Focusing on mental abstraction, we propose that positive mood contributes to a processing style characterized by reliance on prior knowledge in the form of general knowledge structures, whereas negative mood elicits a processing style characterized by attention to details and consideration of new situation-specific information.