Ceramide and its derivatives have been implicated in cellular activation, differentiation, survival and death. Although the main biological function of ceramide appears to be linked to its potency to induce cell death, its actual relevance as a regulator of cell death has been the subject of controversial discussions. Here, we discuss the significance of ceramide in T-cell biology, with special emphasis on the regulation of T-cell receptor expression, growth arrest, costimulation and death.