The mere exposure effect is the commonly observed increase in pleasantness ratings of stimuli that have been given prior exposure. According to the fluency attribution account of the mere exposure effect, repeated presentations of a stimulus lead to increased ease of processing, which in turn is attributed to pleasantness. If so, processing fluency manipulated by means other than repetition should influence liking. In the present experiment, processing fluency was manipulated using a negative priming procedure, and its influence on affective judgement was examined. Previously ignored stimuli were responded to slower (negative priming) and were rated as less pleasant than controls. It was concluded that decreased processing fluency decreases liking of previously ignored stimuli.