Processing or cognitive fluency is the experienced ease of ongoing mental processes. This experience infl uences a wide range of judgments and decisions. We present a general model for these fluency effects. Based on Brunswik’s lens-model, we conceptualize fluency as a meta-cognitive cue. For the cue to impact judgments, we propose three process steps: people must experience fluency; the experience must be attributed to a judgment-relevant source; and it must be interpreted within the judgment context. This interpretation is either based on available theories about the experience’s meaning or on the learned validity of the cue in the given context. With these steps the model explains most fl uency effects and allows for new and testable predictions.