Nanopillar sheets were fabricated with high-aspect ratio structures with a diameter of 160-1000nm and a height of 1μm by nanoimprinting. The suitability of nanopillar sheets as a new type of cell culture dish was examined by studying the behavior of HeLa cells cultured on the sheets using light microscopy, scanning electron microscopy, and fluorescence microscopy observing actin and vinculin molecules. The nanopillar structure enabled easy subculture of the cells from the sheets without conventional trypsinization. Moreover, the HeLa cells divided and proliferated on the sheets in a different way to that found on petri dish because of the manner in which the cells adhered to the materials. © The Japanese Society for Artificial Organs 2006.