Nanocrystalline thin films of La0.67Ba0.33(Mn1−xAlx)O3(x=0.00,0.05,0.10, and 0.15) were prepared by sol-gel method, as a starter material consisting of La2O3, BaNO3, Mn(NO3), and Al(NO3). The molarities of La2O3and BaNO3are constant, while molarities of Mn(NO3) and Al(NO3) were calculated based on stoichiometric theory. Thin films were deposited on quartz glass substrate by using spin coating technique and sintered at 700°C. X-ray diffractometer (XRD) patterns showed that these thin films consist of pure La0.67Ba0.33(Mn1−xAlx)O3phase where the most prominent peak is observed at (104). All the samples display a rhombohedral structure. Scanning electron microscopy (SEM) showed that aggregation of small particles occurred more in doped films than in undoped films. The surface morphology has been studied by using AFM, and the roughness of thin films was analyzed.