Monoclonal antibodies represent the major class of biopharmaceutical products (for therapeutics and diagnostics) with an increasing demand that reaches several tons per year worldwide. Traditional large-scale manufacturing processes are based on stirred tank bioreactors for the growth of Chinese Hamster Ovary cells (CHO) which requires high initial investments and production costs. Therefore, there is an urgent need for alternative production platforms that can at least act as a complement to the over-exploited mammalian fermentation systems. In this perspective, the use of plants for the large-scale production of biopharmaceuticals (Molecular farming') represents an interesting and mature technology that has already proved its benefits in terms of safety, scalability, rapidity and reduced manufacturing costs. Here we discuss the recent advances in the production of monoclonal antibodies (mAbs) in plant-based platforms such as transgenic plants, tissue and cell cultures and transient expression systems.