The synchronization of numerous cellular events requires complex electric and metabolic cell-cell interactions. Connexins are a family of membrane proteins that constitute the molecular basis of two kinds of channels: gap junction channels (GJCs), which allow direct cytoplasm-cytoplasm communication, and hemichannels (HCs) that provide a pathway for exchanges between the intra and extra-cellular milieu. Both kind of connexin-based channels support intercellular communication via intercellular propagation of calcium waves. Here, we review evidence supporting the role of Ca 2+ in the regulation of GJCs and HCs formed by connexins. Also it is speculated how these connexin-based channels could contribute to the propagation of intercellular Ca 2+ signals.