Natural gas will probably become in the next decades the most important energy fuel in the world. This evolution has emerged the issue of security of its supply in the east Mediterranean area affecting Greece and the Greek Natural Gas Public Corporation DEPA. The fact that most production places in the world are located far away from our region, in areas with political and economical instability, creates uncertainty for the security of supply. Greece is going to play in the near future a very important role as south-eastern gas gate and hub of the European Union offering real solutions for diversity of supply and satisfying its own growing domestic demand. This diversity is served by new infrastructure projects like pipelines and LNG terminal upgrades. A scenario planning methodology has been used in order to study security of supply creating a unique method that fits in the nature of the subject. Factors that affect security of supply in east Mediterranean area have been identified and two basic scenarios for the future state in our region were developed. Recommendations are presented for preventive measures and directions that would secure supply even if the future evolves closer to the undesirable scenario.