Autoimmunity accounts for a significant percentage of human disease and remains a challenging syndrome to treat. While systemic immunosuppression can be beneficial, the associated toxicity of the pharmacologic agents necessitates an antigen-specific approach to silence, eradicate or prevent the genesis of autoreactive immune cells. Gene therapy offers the possibility of providing precise antigen-targeted therapies, thereby sparing the patient the significant toxicity associated with lifelong commitment to chemical immunosuppressives. Gene-based therapies could include, but are not limited to the manipulation of immune networks of tolerance by antigen presentig cell engineering, proinflammatory cytokine blockade using soluble antagonists expressed from viral vectors as well as modulation of immune regulatory networks. The potential utility of gene therapy strategies promoting tolerance in two model autoimmune disorders, type I diabetes mellitus and rheumatoid arthritis are discussed in this review.