We here describe a novel form of cellular communication among thymic epithelial cells, namely intercellular calcium waves. We first characterized the mechanical induction of intercellular calcium waves in different thymic epithelial cell preparations: cortical 1-4C18 and medullary 3-10 thymic epithelial cell lines, and primary cultures of thymic "nurse" cells. All thymic epithelial preparations responded with intercellular calcium wave propagation after mechanical stimulation. In general, the intercellular calcium waves detected in these cells presented a high propagation efficacy reaching 80 to 100 % of the cells within a given confocal microscopic field, with a mean velocity of 6 to 10 µm/s and mean amplitude of 1.4 to 1.7 fold the basal calcium level. As evaluated by heptanol and suramin treatment, our results suggest the participation of both gap junctions and P2 receptors in the propagation of intercellular calcium waves in thymic nurse cells, and the participation of gap junctions in thymic epithelial cell lines. In addition, as ascertained by thapsigargin treatment, intercellular calcium wave propagation in thymic epithelial cell preparations was dependent on mobilization of intracellular calcium stores. Finally, in co-cultures the transmission of intercellular calcium wave was not observed between the mechanically stimulated thymic epithelial cell and adherent thymocytes, suggesting that intercellular calcium wave propagation is limited to thymic epithelial cells, and does not affect the neighboring thymocytes. In conclusion, our data describe for the first time intercellular calcium waves in thymic epithelial cells, and the participation of both gap junctions and P2 receptors in its propagation.