This review summarizes recent advances in our understanding of neuronal T–type calcium channel regulation as well as their physiological and pathophysiological roles. Through their ability to conduct calcium across the cellular membrane at potentials close to the resting potential, T–type calcium channels are critically important for regulating neuronal excitability, both in the central and peripheral nervous system. T–type channels are also linked to an increasing number of neurological disorders such as the absence epilepsy and neuropathic pain. Although there is substantial literature dealing with regulation of native T–type channels, the underlying molecular mechanism has only recently been addressed. It is, therefore, critical to understand the cellular mechanisms that control T–type channel activity and expression, because this could provide important insight into designing novel therapeutic strategies targeting these channels.