The development of a Local Agenda 21 is a new instrument for local communities all over the world towards achieving sustainability. Local Agenda 21 is a long-term action program, which presumes the involvement and co-operation of all social groups in this. The article presents the main principles of the Local Agenda 21 and reports about the experiences of some European countries (especially of Germany). Further it is attempted to estimate the issues of the Local Agenda 21 on the urban planning context in Greece. In spite of the objective difficulties Local Agenda 21 could be a promoter for continuity, decentralization and more participation in the Greek planning process.