Preparation of nanosized SnO₂ electroceramic powders via hydrothermal synthesis was investigated as a function of initial concentration and treatment time in order to understand the formation and growth mechanisms. SnO₂ powder was successfully synthesized from the hydrous tin oxide by hydro- thermal synthesis at 200°C. Crystalline SnO₂ particles with a specific surface area as high as 170 m₂/g were produced in a single step without requiring any calcination process. As initial concentration of metal cation increases from 0.0125 to 0.05 M, an Ostwald ripening type growth process was observed in the crystallite size from 3.1 to 4.6 nm. Evolution of tin oxide particles was also investigated by al- tering the treatment time from 1 to 24 h and a diffusion controlled growth behavior was observed as a function of synthesis time.