This study was designed to test the hypothesis that there are multiple factors of metamemory present in the Metamemory in Adulthood (MIA) questionnaire. Data on seven MIA scales from six separate studies on memory/metamemory relationships (total N = 750) were combined to yield two half-samples for cross-validation purposes. The samples were partitioned into young, middle-aged, and old groups. A multiple group confirmatory factor analysis was then conducted on the data, using the first half sample to develop a model and the second half sample to validate it. Although the models did not fully cross-validate, both analyses indicated that there are at least two higher-order factors in the MIA. The first involves beliefs about self-efficacy in using memory. The second factor combines knowledge about memory and affect concerning memory (e.g., achievement motivation). The analyses also indicated that the factor loadings for the second factor, tentatively labelled Knowledge, were invariant across the three age groups, but that there were age differences in the Self-Efficacy Beliefs factor loadings. The differences were localized to age-related increases in the loadings for the MIA Change and Locus scales. The two factor solution has potential for resolving conflicting results in the literature regarding age differences in both metamemory and metamemory/memory performance relationships.