Judgments of learning (JOLs) refer to explicit predictions regarding the likelihood of remembering newly acquired information on a later test of memory. In recent years, there has been considerable interest in understanding the processes that underlie such judgments. Recent theorizing on this matter has characterized JOLs as inferential in nature--that is, they are derived from the implicit utilization of a variety of different cues of which only some are diagnostic of future memory performance. The present series of experiments examine the potential role for one such cue, namely, perceptual fluency (i.e., the subjective ease of perceiving a stimulus) in guiding JOLs. Using a novel methodological approach adapted from Masson (1986), we demonstrate across 6 experiments that perceptual fluency per se can indeed inform predictions of future memory performance, but that its influence depends on the specific task requirements at the time JOLs are solicited. We discuss these results in relation to experience- versus theory-based contributions to metamemory judgments.