Monoclonal antibodies are the largest class of biopharmaceuticals. They are currently utilized in therapies for cancer, inflammatory and cardiovascular diseases, various infections, respiratory diseases, ophthalmologic diseases and organ transplantations. For each treatment, we need large amounts of expensive monoclonal antibodies, which the current production systems soon won’t be able to produce. However, we could acquire a large number of antibodies with plant production systems. Production of monoclonal antibodies in plants has some advantages over the already existing systems: it is very adaptable, fast, cheap, globally accessible and does not pose a threat for an animal pathogen infection. For editing genome and integrating new properties into the plants the existing methods of genetic engineering and new efficient tools, like for example ZFNs, TALENs and CRISPR/Cas9 are available. We can achieve the expression of the monoclonal antibodies in plants with stable transformation or with transient (temporary) expression. The first plant antibodies were obtained from transgenic tobacco plants (Nicotiana tabacum L). For a successful usage of the transgenic plants in the future, the monoclonal antibodies for treating viral infections (human immunodeficiency virus, Ebola virus, West Nile virus, Junin virus, respiratory syncytial virus and rabies), bacterial infections (anthrax, botulism) and cancerous diseases were produced inside them. Some of the monoclonal antibodies synthesized in the transgenic plants are already at variable development stages, but none of them are in wide-range use or on the pharmaceutical market.