The orientation of cell elongation and the plane of cell division were determined in cells growing under isotropic conditions on a plain glass surface or under anisotropic conditions on a scratched glass surface. Four cell lines were analysed, each showing various degrees of contact guidance. Human skin fibroblasts and the skin keratinocyte cell line HaCaT oriented randomly on the smooth isotropic surface of glass, grew and divided randomly. By contrast, on an anisotropic scratched surface these cells showed contact guidance, elongated along scratches, and their planes of division were perpendicular to the long axis of the cell. In these two cell types there was a high degree of correlation between the cell alignment and the plane of cell division, which shows that extracellular factors can influence or even determine the latter. In cell lines in which contact guidance under anisotropic conditions was less evident, viz. the lung endothelial cell line HLMEC and the skin endothelial cell line HSkMEC, the alignment of cell division planes was less ordered. This report concentrates on quantitative phenomenological descriptions of the orientation of cell division as determined by contact guidance.