In this article, a multi-fractal approach has been employed to study the micromorphology of sputtered aluminium films by radio frequency magnetron sputtering method. The films were prepared at 150 and 200 W on stainless and mild steel substrates of 50 mm by 50 mm by 3 mm dimensions. The substrates and targets were maintained at room temperature. The surface microstructures of the films were imaged using atomic force microscopy (AFM). The images were then subjected to the cube counting method to calculate the fractal dimension (D) and multifractal analysis to comprehend the complex nature of the sputtered Al films. The results show that the fractal dimension increases with power for mild steel substrates and decreases with RF power for stainless steel substrates. The multifractal behaviour determined through mass exponent as a function of moment order, singularity strength as a function of singularity exponent, and generalized fractal dimension as a function of moment order reveals that all the films are multifractal in nature.