This study explored the effect of the perceived social content of affective pictures on the subjective evaluation of affective valence and arousal. For this purpose, we established three categories of social content (pictures without people, with one person and with two or more people). A sample of 161 subjects rated 200 pictures varying in affective valence (unpleasant, neutral, and pleasant), arousal and social content. Results of two-factor analysis of variance, F(4, 157) = 71.7, p < .001, ηp2 = .31, showed that perceived social content influenced the ratings of affective valence, specially for unpleasant pictures, with the greatest social content (two or more people) leading subjects to rate unpleasant pictures with the lowest ratings (all pairwise comparisons’ p < .001). Regarding arousal, F(4, 157) = 64.0, p < .001, ηp2 = .29), the higher the social content, the higher the arousal ratings, but only for pleasant (all pairwise comparisons’ p < .007) and unpleasant (all pairwise comparisons’ p < .001) pictures. Overall, this study demonstrated an effect of the perceived social content on the subjective evaluation of affective valence and arousal of emotional stimuli.