The control of cell movement during development is essential for forming and stabilizing the spatial organization of tissues and cell types. During initial steps of tissue patterning, distinct regional domains or cell types arise at appropriate locations, and the movement of cells is constrained in order to maintain spatial relationships during growth. In other situations, the guidance of migrating cells or neuronal growth cones to specific destinations underlies the establishment or remodelling of a pattern. Eph receptor tyrosine kinases and their ephrin ligands are key players in controlling these cell movements in many tissues and at multiple stages of patterning.