The study of synchronous populations of yeast cells has provided a wealth of information into regulatory aspects of the eukaryotic cell division cycle. Synchronized yeast cultures may also have potential benefit when exploiting yeasts in biotechnology. This paper provides an overview of the methods which have been used in the synchronization of cell division in budding and fission yeasts. The relative merits of these methods are outlined and protocols for preferred synchronization methods, based on size selection techniques, are described. In particular, centrifugal elutriation protocols for Saccharomyces cerevisiae (budding yeast) and Schizosaccharomyces pombe (fission yeast) are detailed as this method is regarded as one of the best ways of preparing 'unperturbed' synchronous yeast cultures for cell cycle studies.