The mammalian protein kinase C (PKC) superfamily plays regulatory roles in many different cellular processes. However, due to the many members that exist in cells, it is very complicated to present experimental evidence of the particular function of each member. In contrast, yeasts have only one or two PKC members and genetic tools have unveiled their role as main regulators of cell integrity. In this review, we will discuss the function of yeast protein kinase C homologues, their mechanism of activation and the signalling pathways that they regulate in two model yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe.