Technical Abstract: The use of transgenic plants as vectors for the expression of viral and bacterial antigens has been increasingly tested as an alternative methodology for the production of experimental vaccines. Here, we report the production of transgenic alfalfa plants containing the genes encoding for the polyprotein P1 and the protease 3C of foot and mouth disease virus (FMDV). The immunogenicity of the expressed products was tested using a mouse experimental model. Parenterally immunized mice developed a strong antibody response detected by its reactivity, in ELISA, against a synthetic peptide representing the most immunogenic area of VP1 and purified FMDV particles and, in Western blot, against the native virus structural proteins, VP1, VP2 and VP3. Additionally, these mice were complete protected against the experimental challenge with the virulent virus. This report demonstrates the possibility of using transgenic plants to express highly complex antigenic structures and its utilization as effective experimental immunogens.