--- - |2 Abstract The stimulus‐preceding negativity (SPN) is a reliable index of incentive anticipation. However, it remains controversial whether the anticipatory process indexed by the SPN is modulated by incentive valence. The present study investigated the effect of valence on the SPN in a gambling task that required participants to make a binary (gain vs. loss) prediction after their choice on trials with different reward probabilities. Behaviorally, the participants exhibited a positive bias in their prediction. Electrophysiologically, a valence asymmetry was observed for the SPN. Specifically, the SPN was more pronounced when the participants made a gain relative to loss prediction, which was specific over the left hemisphere. Moreover, the SPN showed an uncertainty effect with enhanced amplitudes before uncertain versus certain outcomes, which tended to be pronounced during gain compared to loss anticipation. These findings indicated that the SPN is more sensitive to positive relative to negative valence, which may be mediated by the mesocorticolimbic dopaminergic pathway.© 2018 Society for Psychophysiological Research - Psychophysiology, Volume 55, Issue 11, November 2018.