To use transgenic potato tubers (Solanum tuberosum cv. Désirée) for bulk production of recombinant antibodies, constructs were engineered for accumulating full-size IgGs and Fab fragments in the plant cell apoplast or endoplasmic reticulum (ER). An in-house transformation protocol was worked out for the efficient co-transformation of potato root explants. Accumulation levels in tubers of up to 0.5% of total soluble protein were found for antibodies targeted to the ER whereas five-fold lower accumulation levels were found for antibodies targeted for secretion. Additionally, different aspects important for the commercial exploitation of potato tubers as a heterologous production system were analysed. Tubers could be stored for up to 6 months without significant loss of antibody amount or activity. Minor variations in antibody accumulation levels were observed in tubers that originated from the same transformant. Most isolated IgGs and Fab fragments bound the antigen and had the correct molecular weight when compared with the hybridoma-derived standard. Processing to greenhouse or field trials, including in vitro propagation of a selected transformant, required only approximately 9 months from the start of transformation, a time frame in which hundreds of kilograms of transgenic potato tubers could easily be obtained. Small-scale purification of IgG was possible by using standard laboratory techniques. Thus, molecular farming in potato tubers can be a viable production system for economic production of clinically or industrially interesting macromolecules, such as antibodies.