Internalization of cell-penetrating peptides, well described in mammalian cell system, has recently been reported in a range of plant cells by three independent groups. Despite fundamental differences between animal cell and plant cell composition, the CPP uptake pattern between the mammalian system and the plant system is very similar. Tat, Tat-2 pVEC and transportan internalisation is concentration dependent and non saturable, enhanced at low temperature (4 degrees C), and receptor independent. The use of CPPs as nanocarrier for macromolecular delivery in plant cells is now achievable and the advances made in mammalian cells greatly enhance our understanding of cell-membrane and CPP-macromolecule complex interaction in plant. The cross membrane nanocarrier ability of CPPs promises new avenues in the field of plant biotechnology.