Genetic immunization with lentiviral vectors is under evaluation as a means for induction of sustained immune response. Lentiviral vectors showed reduced antivector immune responses and efficiently transduce post-mitotic cells in vivo, including antigen presenting cells, such as dendritic cells and macrophages, thus providing a significant benefit over other vector-based antigen delivery platforms. Several evidences indicate that a single immunization with lentiviral vectors induces strong and sustained effector and memory T-cell immune responses, as well as antibody production. New generation of lentiviral vectors with improved biosafety profile are also under development. In particular, integration defective lentiviral vectors have been generated and used as an efficient and safe delivery system for both gene therapy and immunization purposes. Taken together, these evidences support the ongoing development of lentiviral vector-based genetic immunization strategies for safe applications in the clinic.