Successful cell division requires that daughter cells inherit not only a complete set of chromosomes, but also only one centrosome, and similar amounts of organelles and cytoplasmic components. The different mitotic processes are driven by cell cycle-regulated protein kinases and phosphatases and their fidelity is closely monitored by a number of checkpoint mechanisms. Histone H3 is phosphorylated during mitosis, but the kinases involved were not known until recently. Recent work has revealed that Aurora kinases are required for mitotic phosphorylation of histone H3 and of its centromeric variant CENP-A. This finding has stimulated functional studies of the role(s) of Aurora kinases and H3 phosphorylation during mitosis, which are reviewed in this chapter.