Neurons in ferret (Mustela putorius furo) auditory cortex respond to simple visual stimuli and auditory responses to broadband noise can be modulated by the presence of visual stimuli (Bizley et al., 2007). Visual interactions in auditory cortex may arise from input connections from neurons in visual cortex, parietal cortex and the suprageniculate nucleus of the thalamus (SGN). However the functional relevance of these inputs remains to be demonstrated. Here, we investigated the role of a sub-region of visual cortex – the suprasylvian cortex (SSY) – in multisensory integration. SSY sends dense projections to auditory cortex, particularly regions of anterior auditory cortex and we studied the effects of SSY inactivation on responses of auditory cortical neurons. Multi-unit neural activity was recorded at 13 sites within the auditory cortex of three ferrets anesthetized through intra-venous administration of ketamine (5 mg kg-1 hr-1) and medetomidine (0.022 mg kg-1 hr-1). Neural activity within auditory cortex was recorded before and during inactivation using cooling loops that reduced the cortical surface temperature of SSY to between 4 and 7°C. Simultaneous recording of neural activity within SSY of two ferrets confirmed the efficacy of inactivation through cooling. Auditory cortical units were found in which cooling significantly reduced visual but not auditory responses. Furthermore units were found in which visual modulation of auditory responses was selectively reduced by cooling. We also found evidence for the involvement of regions outside of SSY as several units demonstrated visual responses robust to cooling. Units were also discovered for which cooling reduced visual responses but only within a circumscribed period of the response. Additionally in sporadic cases, cooling led to the emergence of visual responses or the visual modulation of auditory responses within auditory cortex. Together these preliminary findings support the role of SSY in multisensory integration within auditory cortex, but also indicate the involvement of additional brain regions possibly including other subdivisions of visual cortex, parietal cortex and SGN. Our results also suggest that SSY inputs to auditory cortex may involve both excitatory and inhibitory mechanisms. Future work will focus on elucidating the contributions of regions beyond SSY to visual activity within auditory cortex and their relevance for behaviour.