Plants are promising vehicles for the expression of recombinant proteins with regard to medical and veterinary purposes. In order to enhance the accumulation of two HIV-1 neutralizing antibodies (2F5 & 2G12) in tobacco plants and to simplify the purification, synthetic repeats of elastin- like polypeptides (ELPs) were C-terminally fused to both antibody chains. Crossing of transgenic plants with accumulation of the individual antibody chains in all combinations resulted in transgenic lines producing the complete antibodies in four formats, with ELP on either the light or heavy chains, on both or on neither. An increase of the expression caused by ELP fusion was confirmed for the individual antibody chains and for the full-length antibodies. Homozygous tobacco lines were produced by embryogenic pollen culture and the genome of the generated haploids was doubled. Characterization of the affinity-purified antibodies from tobacco leaves by surface plasmon resonance spectroscopy showed that the kinetic binding parameters were identical to those of in CHO (Chinese hamster ovary) cells produced counterparts lacking ELP. N-Glycan analysis of these preparations revealed that all four derivatives of 2F5 and 2G12 contained predominantly oligo-mannose type N-glycans. In vitro neutralization assays demonstrated that the HIV-1 inactivation capacity of the tobacco produced 2G12 was equivalent or even better compared to the CHO standard. ELP fusions do not interfere with folding, assembly, trafficking in the secretory pathway, or post-translational modification. First experiments on the enrichment of recombinant antibody ELP fusions in tobacco leaf extracts were performed and indicated a simplified recovery of the recombinant proteins.