Thin films (0.12 mu m) of hematite (alpha-Fe2O3) were prepared on Si(111) and Si(100) substrates by hydrothermal treatment of a solution of iron nitrate containing urea in the temperature range of 100-200 degrees C for 4-24h. The films consisted of spherical grains for Si (111) and columnar grains for Si(100) with a typical grain size 10nm and 30nm x 5nm, respectively. Both films deposited on Si (111) and Si(100) have (101) preferred orientation.