If the demand for environmental goods is increasing with income, democratization shifts the decisive power from a rich autocrat to a poorer individual (decisive voter), so it should be associated with worse environmental conditions. In this paper, it is shown through a theoretical model that: (i) democratization may have mixed effects on the level of environmental quality, depending on the size of the price and income effects on the demand for environmental quality associated with a decrease in the decisive political actor's wealth; and (ii) assuming that society is composed of two classes of individuals with different levels of exposure to pollution, and assuming moreover that the decisive voter belongs to the most exposed class of individuals while the autocrat does not, democratization is beneficial for the environment, and the better the effect on the environment, the bigger the difference in wealth between the two decisive political actors.