The use of atomic force microscopy for the characterization of Fe2O3 nanopowders is discussed and demonstrated with several experimental examples related to the new exhibitions of polymorphism in the nanoworld. Due to the rare literature data concerning the application of AFM in the analysis of iron oxide particles, our experimental experience, advantages and drawbacks of this microscopic technique including the comparison with the conventionally used TEM are described. The influence of sample preparation, possible artifacts and image deformations on interpretation of AFM data is emphasized.