The experience of fluency while learning might bias students’ metacognitive judgments of learning (JOLs) and impair the efficacy of their study behaviors. In the present experiments, we examined whether perceptual fluency affects JOLs (1) when people only experience one level of fluency, (2) when item relatedness is also available as a cue, and (3) across study-test trials. Participants studied a list of paired associates over two study-test trials and made JOLs for each item after studying it. We varied the perceptual fluency of the memory materials by making the font easy (fluent) or difficult (disfluent) to read. We also varied whether we manipulated the perceptual fluency of the items between-participants or within-participants and whether other memory factors—item relatedness and study time—were available for participants to use to inform their JOLs. We were only able to obtain effects of perceptual fluency on JOLs when we manipulated fluency within-participants and eliminated item relatedness as a cue for JOLs. The present results indicate that some effects of perceptual fluency on JOLs are not robust and might only occur under limited—and somewhat contrived—conditions. Therefore, these effects might be unlikely to bias students’ JOLs in actual learning situations.