Altough its very ancient roots, urbanization in Algeria is very recent when considering its extent. Five generally accepted ideas on Algerian urbanization are analysed here. It is thus proved that the fondations of these ideas are not always exact and must be qualified. However, if the growth of urbanization is a phenomenon common to all three countries of the Maghreb, its specific characteries in Algeria are shown by the more unbalanced situation of the towns, more traumatizing than for her Maghreb neighbours. In this way, a favourable ground has been created for the rise of the Islamic movement. It seems that the explanation of this situation lies in the way this urbanization has been carried out.Bien que fort ancienne par ses racines, l...