Evidence for a Ca2+-pump at the nuclear envelope (NE) in plant cells has been obtained using confocal and electron microscope immunocytochemistry and antibodies raised to a plant homologue of the mammalian SERCA pump. This is the first evidence suggesting an NE Ca2+-pump in plants. In addition to being localised with the NE in interphase, the antigen was localised to membrane derived from the NE and associated ER during mitosis, correlating with known Ca2+-pools. The work suggests that a SERCA pump is present at the NE of plant as well as animal cells.