This paper is a review of studies on on-line political discussions. Originally these studies were strongly influenced by the deliberative issue, but the academic literature now stresses the socio-technical devices used and the objectives of these discussions. Even though on-line political discussions can lead to the homogenization of opinions, they are also open to diverse opinions and to a wide range of discursive resources. The need for further research on citizens' motives for taking part in on-line discussions, as well as the effects of these discussions on political engagement and public decisionmaking, is also underlined.