Background. Foot and mouth disease (FMD) is a highly contagious and economically devastating disease of cloven-hoofed animals. The goal of the present study was to increase the efficacy of FMD vaccines by co-administration of Echinacea (herbal medicine for enhancing the immune system), Methods. Two dairy farms (I&II) containing 1620 cows and calves were firstly monitored by nonstructural proteins (NSPs) antibody test for identifying the previous or current infections. The non-infected calves of 4 months old were selected in the 2 farms and divided into 4 groups of 90 calves. Group A was vaccinated with imported FMD vaccine (Raksha-Ovac, India) alone. Group B was vaccinated with imported FMD vaccine associated with Echinacea. Group C was vaccinated with local FMD vaccine alone and, Group D was vaccinated with local FMD vaccine associated with Echinacea. The efficacy of such vaccine either alone or associated with Echinacea were evaluated by determination of the antibody titers in the sera of vaccinated animals by ELISA and SNT. Results. The results of NSPs antibody test revealed that 12 animals out of 820 were infected in farm I while 10 out of 800 were infected in farm II, ELISA and SNT results showed that, the protective antibody level was higher in sera of group B than group A in farm I and in group D than group C in farm II. This level was generally higher in farm I than farm II and continued until the 32^nd and 40^th week post-vaccination in group A and B of farm I respectively while in farm II it continued until the 20^th and 24^th week post-vaccination in group C and D, respectively. Conclusion. The association of Echinacea significantly enhanced the efficacy of both FMD local and imported vaccines and this is the first paper, to our knowledge, that described the association of Echinacea with FMD vaccines in the veterinary field with its use in treatment of infected animals.