The auditory sensory gating system modulates its sensitivity to incoming stimuli and prevents higher brain functions from sensory overload in the primary auditory cortex. We investigated whether visually evoked emotional stimuli affect auditory sensory gating. Magnetic P50 (P50m) suppression was evaluated by magnetoencephalography in fifteen healthy subjects while they viewed slides varying in emotional valence and arousal. The ratio of strength of dipole moments of the 2nd to the 1st P50m and the anatomical location of their sources were calculated. Negatively valenced slides significantly attenuated P50m suppression, as compared to neutral ones, while the effects of positive slides were insignificant. No effects on latencies or the location of P50m sources were observed. Thus, negative emotional stimuli may modulate sensory gating.