Contemplative mental practices aim to enable individuals to develop greater awareness of their own cognitive and affective states through repeated examination of first-person experience. Recent cross-sectional studies of long-term meditation practitioners suggest that the subjective reports of such individuals are better calibrated with objective indices; however, the impact of mental training on metacognitive ability has not yet been examined in a randomized controlled investigation. The present study evaluated the impact of a 2-week meditation-training program on introspective accuracy in the domains of perception and memory. Compared with an active control group that elicited no change, we found that a 2-week meditation program significantly enhanced introspective accuracy, quantified by metacognitive judgments of cognition on a trial-by-trial basis, in a memory but not a perception domain. Together, these data suggest that, in at least some domains, the human capacity to introspect is plastic and can be enhanced through training.