Protein kinase C (PKC) is involved in the control of many key signaling pathways in cells. Investigations over the past decade have shown that many effects of ethanol on cell function are closely interconnected with PKC. Three distinct areas of investigation have emerged; they are reviewed in this article. In vitro studies show that ethanol and higher alcohols can both inhibit or enhance PKC activity, depending on the experimental conditions. These studies show that alcohols interact directly with PKC, suggesting at least some role of this interaction in intoxication and anesthesia. Most ion channel systems are modulated by ethanol to varying degrees, and inhibition of PKC attenuates this effect; however, the mechanism by which ethanol brings about this effect is not known. Lastly, prolonged or chronic ethanol exposure up-regulates PKC, an effect that has important consequences, for example, in neuronal development; again, the mechanism leading to this process is not understood. The current consensus is that PKC is intimately involved in acute and chronic ethanol action, and the challenge now is to determine the mechanisms involved so that strategies can be developed to control these effects.