Zirconia- supported iron-based Fischer-Tropsch catalysts were prepared using incipient wetness impregnation. The choice of the precursor, in this case the chelating ammonium iron(III) citrate, and the applied calcination temperature determine the final distribution of the precursor on the zirconia support. Several techniques reveal that both an unpromoted and a potassium-promoted catalyst can be prepared, of which the iron(III) oxide exhibits a high dispersion and is, moreover, monodisperse.