Memory knowledge may be necessary but not sufficient for strategy use because aspects of the individual and the task may mediate the metamemory-strategy use relation. Belmont and Mitchell (1987) contended that learners will be strategic only on tasks perceived to be moderately difficult. If correct, metacognitive variables (e.g., metamemory and attributional beliefs) would be more likely to predict strategy use on moderately difficult tasks. In the study presented here, strategy use, performance, and perceptions of difficulty among students with and without retardation were assessed. Results showed that students with mental retardation rated tasks as more difficult than did nonretarded students. Relatedly, brief training resulted in a decrease in difficulty ratings only for students without retardation. Although strategy use was not predicted by metacognitive variables (meta-memory and strategy use) on moderately difficult tasks, metacognitive variables significantly predicted recall performance, but did so independent of task difficulty.