The functioning of eukaryotic cells is strictly dependent on the proper vesicular traffic within the cell’s membrane system. Brefeldin A – a fungal toxin, disturbs this traffic, enabling an experimen- tal insight into the organisation and co-operation of various elements of the system. Recently, BFA target proteins and sites of action have been identified. In this paper, we analyse the mechanism of BFA functioning and indicate those particular properties of the membrane system of plant cells that determine some of the reactions to BFA that are specific to plants. We demonstrate also, how the research into one of such reactions – the formation of BFA compartments has led to the discovery of novel aspects of endocytosis in plants. Finally, we identify implications, born from the recognition of the mechanisms of BFA action, for the modern concepts of molecular and cellular mechanisms of polar auxin transport.