The influence of sputtering substrate temperature on the microstructure and wear properties of aluminum thin films deposited on stainless steel substrates by radio-frequency (RF) magnetron sputtering was studied. The aluminum films were deposited on stainless steel substrates at different temperatures of 70°C, 80°C and 100°C and at a constant power of 300 W. The surfaces of the films were then characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), surface profiling and wear methods. The wear was undertaken at extremely high sliding load of 50 N. Fine-grained and smooth microstructures exhibiting hillocks were observed at 70°C whereas coarse-grained and rough microstructures consisting of porous structures were obtained at 100°C. Defect-free and well-defined microstructures were obtained at 80°C. All the films obtained within this range of temperatures were crystalline according to the XRD results. Films obtained at 80°C were shown to have the highest coefficient of friction whereas those deposited at 100°C exhibited the lowest wear resistance. The films' failure along the edges of the balls under high sliding load were characterized by thinning, deformation and tearing (cracking).