This work presents a morphological study of polyaniline (PANI) films, chemically and electrochemically synthesised over ITO (Indium Tin Oxide covered glass) substratum using atomic force microscopy (AFM). From AFM images we calculate the fractal dimension of the polyaniline formed films using power spectral density (PSD) and the box counting method (roughness versus scale). As a result it is shown that the fractality obtained by PSD are in good agreement with box counting.374 191200Gonzalez, R.G., Wintz, P., (1987) Digital Image Processus, , Addison-Wesley, ReadingVatel, O., Dumas, P., Chollet, F., Salvan, F., André, E., Roughness assessment of polysilicon using power spectral density (1993) Jpn. J. Appl. Phys., 32, p. 5671Mitchell, M.W., Bonnel, D.A., Quantitative topographic analysis of fractal surfaces by scanning tunneling microscopy (1990) J. Mater. Res., 5 (10), p. 2244Mandelbrot, B.B., (1983) The Fractal Geometry of Nature, , W. H. Freeman and Company, New YorkMandelbrot, B.B., (1977) Fractals Form, Chance, and Dimension, , W. H. Freeman and Company, San FranciscoMandelbrot, B.B., Passoja, D.E., Paullay, A.J., Fractal character of fracture surfaces of metals (1984) Letters to Nature, 308, p. 721Vatel, O., Dumas, P., Chollet, F., Salvan, F., Andre, E., Roughness assessment of polysilicon using power spectral density (1993) Jpn. J. Appl. Phys., 32, p. 5671Barabási, A.L., Stanley, H.E., (1995) Fractal Concepts in Surface Growth, , Cambridge, Cambridge University PressRuss, J.C., (1994) Fractal Surfaces, , Plenum Press, New York and LondonKiely, J.D., Bonneli, D.A., Quantification of topographic structure by scanning probe microscopy (1997) J. Vac. Sci. Technol. B, 15 (4), p. 1483