In this study, Eu-doped SnO2 thin films were prepared by a metal organic decomposition method through a pyrolysis of organic acid salts. The effects of annealing temperature and Eu concentration on the structural and photoluminescence properties of the films were investigated. X-ray diffraction measurements showed that the crystal structure corresponded to tetragonal rutile SnO2 regardless of the annealing temperature or Eu concentration. Additionally, X-ray diffraction, Fourier transform infrared spectroscopy and atomic force microscopy measurements indicated an improvement in crystalline quality with increasing annealing temperature. Photoluminescence spectra exhibited Eu-related emissions around 588–599 nm and 620 nm. It was found that the photoluminescence properties were strongly dependent on both the annealing temperature and Eu concentration. The highest photoluminescence intensity around 588–599 nm was obtained for an Eu concentration of 7.2 at.% for samples annealed at 1000 °C.