Viral pathogens are responsible for a significant number of human diseases ranging from the common cold to chicken pox to HIV/AIDS. This upper level undergraduate course will cover the history and discovery of viruses. We will review viral structure, replications, and pathogenesis. This course will introduce students to bacteriaphages as well as plant and animal viruses. We will introduce the similarities and differences between RNA and DNA viruses as well as explore the mechanisms responsible for viral entry into cells, viral protein expression, viral assembly, and viral replication. We will discuss acute, persistent, and latent infections. Students will learn about important viral diseases in humans and animals and will learn how viral infection can contribute to malignancy. In addition, the interactions between the host immune response and the viral virulence mechanisms will be discussed. Course grade will be based on both exams and a student project. Overall, students will gain a fundamental understanding of viral structure, biology, pathogenesis, and control.