Viruses interact with the host ubiquitination system in a variety of ways. Viral proteins are often a substrate for ubiquitination, which leads to proteasomal degradation. Viruses also have functions to modify the cellular ubiquitination machinery. Recently, deubiquitinating protease (DUB) activity has been found in many viral proteins. In herpesviruses, the DUB domain is found within the large tegument protein, which is conserved in all members of the herpesvirus family. Although a limited number of viral and cellular targets have been identified to date, accumulating evidence shows that herpesviral DUBs may primarily target key cellular regulators of immune signaling pathways to promote viral replication. In this review, we summarize the recent findings on viral DUBs. In particular, we focus on the herpesviral DUBs and their targets, and discuss their potential roles in the regulation of immune signaling pathways.