Ubiquitination and deubiquitination regulate several essential cellular processes such as protein degradation, cell-cycle progression, signaling, and DNA repair. Given the importance of these processes, it is not surprising that many microbes have developed the means to interfere with different stages of ubiquitin pathways to promote their survival and replication. This review focuses on virulence proteins of bacterial pathogens that mediate these effects and summarizes our current understanding of their actions.