The fission yeast Schizosaccharomyces pombe provides a simple eukaryotic model for the study of cytokinesis. S. pombe cells are rod-shaped, grow mainly by elongation at their tips, and divide by binary fission after forming a centrally placed division septum. Analysis of mutants has begun to shed light upon how septum formation and cytokinesis are regulated both spatially and temporally. Some of the proteins involved in these events have been functionally conserved throughout eukaryotic evolution, suggesting that aspects of this control will be common to all eukaryotic cells.