Neurons in the auditory cortex (AC) respond to acoustic stimuli in diverse ways. Short latency responses code for the physical properties of stimuli, i.e., their frequency and intensity, whereas longer latency potentials may code for behavioral significance or other features. Despite a huge number of studies that, over the years, have reported on acoustic-evoked short and long-latency potentials, remarkably little is understood regarding the cellular mechanisms underlying these responses. Such information is critical to a full understanding of auditory information processing. This review summarizes the available data on synaptic and cellular mechanisms in AC neurons that have been obtained using electrophysiological methods with in vivo and in vitro preparations. It is apparent that the fundamental mechanisms identified in recent studies can be used in the near future to develop an integrated understanding of the cellular bases of information processing in auditory cortex.