The antiviral effect of monoclonal antibodies MAK-14-7 possessing the neutralizing activity was studied on the model of Venezuelan equine encephalomyelitis virus in cell cultures and in experimentally infected laboratory animals. Mouse monoclonal antibodies exerted a marked specific antiviral effect in tissue culture and in white mice inhibiting virus reproduction by 1-3-5 log PFU/ml. The degree of inhibition of virus reproduction is inversely proportional to the multiplicity of infection. When used in combination with remantadine, ribavirin, interferon, and its inducer poly (I) X poly (C), the monoclonal antibodies MAK-14-7 exerted additive antiviral effect.