Advances in molecular biology, immunology, and plant biotechnology have changed the paradigm of plant as a food source to so-called plant bioreactor to produce valuable recombinant proteins. These include therapeutic or diagnostic monoclonal antibodies, vaccines, and other biopharmaceutical proteins. The plant as a bioreactor for the production of therapeutic proteins has several advantages, which include the lack of animal pathogenic contaminants, low cost of production, and ease of agricultural scale-up compared to other currently available systems. Thus, plants are considered to be a potential alternative to compete with other systems such as bacteria, yeast, or insect and mammalian cell culture. Plant production systems, particularly therapeutic antibodies, are very attractive to pharmaceutical companies to produce the antibodies in demand. Currently, we have successfully developed a plant system for production of anti-rabies monoclonal antibody and anti-colorectal cancer monoclonal antibody. The effective plant production system for recombinant antibodies requires the appropriate plant expression machinery with optimal combination of transgene expression regulatory elements, control of posttranslational protein processing, and efficient purification methods for product recovery. However, there are several limitations that have to be resolved to establish the efficient plant system for antibody production. Here, we discuss the approaches and perspectives in plant systems to produce monoclonal antibody.