Two experiments examined the processes by which positive and negative mood states produce attitude change under high elaboration conditions. We hypothesized that under high elaboration conditions, mood would influence attitudes by affecting the perceived likelihood of occurrence for consequences presented in message arguments. In Experiment 1, arguments were framed positively, and positive mood led to greater perceived likelihood of the consequences and more favourable attitudes than negative mood for subjects high in need for cognition (NC). In Experiment 2, arguments were framed either positively or negatively, and a mood X frame interaction was obtained on attitude and likelihood judgments for high-NC subjects. That is, positive mood led to marginally greater perceived likelihood of positive consequences but to lower likelihood of negative consequences as compared to negative mood As a result, positive mood tended to lead to more persuasion than negative mood when the message was framed positively, but to less persuasion when the message was framed negatively. In both experiments, path analyses supported the prediction that likelihood judgments mediated the impact of mood on attitudes for high-NC individuals.