Submicrometric magnetic structures have been fabricated by electron-beam lithography on Si substrates. High-quality patterns have been obtained with typical length scale of the structures in the range of 100 nm. The designed geometrical configurations are suitable for investigation of their physical properties by transport measurements in a controlled way. In particular, long chains of connected magnetic dots are useful to analyze magnetization reversal processes, whereas ordered arrays of isolated dots can be used to study pinning effects in superconducting films. © 1998 American Institute of Physics.