Magnetic and structural properties of gamma iron oxide thin films depend significantly on the orientation of the substrate with respect to the direction of source vapour during the growth of films by the reactive chemical vapour dissociation technique. Formation of large grains and grain clusters is observed for flat deposited films as compared with compact small grains at oblique incidence. Such structural variation modifies the anisotropy in the film, resulting in high coercivity of 770 Oe and remanence of 2.7 kG in undoped gamma-Fe2O3 films.