Rotaviruses cause severe dehydrating diarrhea and are a leading cause of death in children worldwide. A potent antiviral, interferon-a (IFNa), is rapidly secreted by plasmacytoid dendritic cells (pDCs) in response to viral single-stranded RNA or DNA genomes. Here, we examined the effects of rotavirus on pDCs purified from human blood. We found that very few pDCs supported rotavirus replication, and that pDCs retained similar functionality in response to live or inactivated rotaviruses. While pDCs produced large quantities of IFNa shortly after rotavirus exposure, this was impaired in cells supporting viral replication. We also found that two viral proteins and the rotavirus double-stranded RNA genome were required for the initiation of the pDC IFNa response to rotavirus. Additionally, we found that cleavage of one of these viral proteins, a traditional prerequisite for rotavirus infection in other cell types, was not required for the infection of pDCs or production of IFNa. This may enable the host to rapidly initiate an immune response to rotavirus that subsequently restricts infection to the intestine and contributes to the resolution of disease. Our study provides novel insight into the interaction between rotavirus and the host innate immune response, and also identifies a unique mechanism for the production of IFNa by pDCs.