Emotion regulation can be achieved through a number of processes. Previous studies have investigated this issue by encouraging individuals to voluntarily change how they think about a situation in order to decrease its emotional impact. However, little is known about automatic regulation processes. The goal of the present study was to investigate whether an "implicit reappraisal strategy" would modulate the Late Positive Potential (LPP) associated to affective picture viewing. Unpleasant pictures, presented as distractors, were shown in two contexts in which a prior description presented them as taken from either movie scenes (fictitious) or real scenes. Results showed that the interference produced by unpleasant pictures under the real context, indexed by reaction time and LPP amplitude, was attenuated under the fictitious context. These results provide evidence for implicit down-regulation of the stimulus relevance during an inattention condition.