Since the identification of clathrin as a vesicular coat protein, numerous studies have contributed to our understanding of the role of clathrin and clathrin-mediated trafficking pathways in cell function. The budding yeast, Saccharomyces cerevisiae, offers a wealth of highly developed approaches that have been applied to study clathrin-mediated trafficking events, most of which are conserved in mammalian cells. Here we review the function of clathrin and clathrin adaptors in yeast. We also discuss the role of these proteins in human disease and how certain pathogens have co-opted trafficking pathways for their own use. These studies highlight the advantages of studying complex trafficking events using yeast as a model.