Tin valerate films have been prepared by spincasting solutions produced from the hydrolysis of tin(II) methoxide or tin(TV) isopropoxide in alcohol and valeric acid. Tin oxide films were made from tin valerate films using two methods : calcination at 400 degrees C in air and by room temperature hydrogen peroxide treatment. AU tin valerate and tin oxide films are transparent and exhibit uniform adhesion to quartz substrates. FTIR and XPS analyses indicate that the structure and composition of valerate films prepared from either alkoxide are similar despite differences in precursor oxidation state and concentrations of acid and alcohol used for the syntheses. Tin valerate films are comprised of an oxygen-tin polymer backbone coordinated with valerate ligands. Both monodentate and bidentate carboxylates are present, the former apparently stabilized by hydrogen bonding with sorbed water. Quantitative XPS analysis indicates that valerate/tin and hydroxyl/tin ratios are 0.26 and 0.55, respectively. This level of film carboxylation is consistent with the extent of carboxylate formation in tin(IV) isopropoxide/valeric acid solutions. Hydrogen peroxide treatment of tin valerate films removes organic ligands and increases the level of backbone oxygen. Hydrogen peroxide treatment or calcination results in the formation of amorphous tin(TV) oxide films.