<p>Fluent (i.e., rapid and efficient) processing of perceptual objects is vital for humans to successfully navigate their environments. The experience of fluent processing per se tends to trigger positive affect; however, this affect is often misattributed by perceivers to the objects themselves, meaning that easy-to-perceive objects are judged more positively. These fluency-based preference effects have been robustly demonstrated unimodally, and specifically in situations in which fluency and preference are manipulated and measured for the same objects. However, little is known about how this effect operates crossmodally, when manipulations of fluency in one domain are combined with preference judgements for unmanipulated objects in another domain. In six experiments, we manipulated perceptual fluency in a simple auditory task which participants performed whilst viewing visual objects, which they rated for liking. We found that visual objects presented with easier (more fluent) auditory stimuli received higher liking ratings. This effect persisted when a temporal lag was introduced between the auditory/visual components, but was less reliable for static (as opposed to moving) objects. These results show that fluency-based preference effects can operate crossmodally. They have implications for a range of real-world contexts involving preference and attitude change.</p>