The first results of a theoretical study of bromination reactions in solution are presented, with an illustration of the parameters used to describe the solvation effects in the framework of the polarizable continuum model (PCM). The distribution of the positive charge on the atoms of some bromonium ions is calculated, using Bader’s procedure on the wave functions obtained in vacuo, in dichloroethane, and in methanol. These results provide new insights about the nature of bromonium ions and the reversibility of their formation reactions.