A zwitterionic molecule has been incorporated as a Langmuir-Blodgett (LB) film between two electrodes. Current-voltage curves are presented which exhibit rectifier-like behaviour. By placing passive organic layers between the zwitterionic LB film and each electrode we show that Schottky contact and similar interfacial effects axe not important and, therefore, that the rectifier-like behaviour is unequivocally associated with the zwitterionic molecular structure.