Sn1-xMnxO2 (x <= 0.11) thin films spin-coated on Si (1 1 1) substrate were fabricated by sol-gel method. X-ray diffraction revealed that single-phase rutile polycrystalline structure was obtained for x up to about 0.078. Evolution of the lattice parameters and X-ray photoelectron spectroscopy studies confirmed the incorporation of Mn3+ cations into rutile SnO2 lattice. Magnetic measurements revealed that all Sn1-xMnxO2 thin films exhibit ferromagnetism at room temperature, which is identified as an intrinsic characteristic. Magnetization data showed that the average magnetic moment per Mn atom decreased and the coercivity increases with increasing Mn content. The origin of room temperature ferromagnetism can be understood in terms of the percolation of the bound magnetic polaron. Our experimental results prove that the sol-gel method is an effective method for fabrication of transition metal doped SnO2 nanostructures with room temperature ferromagnetism by chemical synthesis. (C) 2008 Elsevier B. V. All rights reserved.