This work describes the synthesis, at room temperature, of doped and undoped SnO2 nanocrystals (particle size ranging from 1-3 nm) with no thermal or hydrothermal treatment. To the best of our knowledge, this is the first time that the synthesis, at room temperature, of doped and/or undoped SnO2 nanocrystals has been reported. This new synthesis method is based on the controlled oxidation, hydrolysis and polycondensation of tin ions in an ethanol solution. Another novel aspect of this method is the possibility of using surfactants, which may provide improved control over the particle size.