We investigate the role of negative emotional stimuli on direct and indirect metacognition, and document age-related differences in this role during adulthood. Participants were presented with negative or neutral pictures while asked to select which of two available strategies was the better strategy to find approximate estimates of two-digit multiplication problems. Following each strategy selection, participants provided either a direct (confidence judgment; Expt. 1) or an indirect (opt-out judgment; Expt. 2) evaluation of their strategy choice. Negative emotional stimuli decreased metacognitive accuracy for arithmetic strategy selection, but only when indirect metacognitive measures were collected. No differences were found when direct metacognitive judgments were requested. The effects of emotional stimuli on indirect metacognition and lack of effects on direct metacognition were found in both young and older adults. These findings have important implications for our understanding of the mechanisms underlying the effects of emotion on metacognition in young and older adults.