The plasma gasification process has been demonstrated in many new studies as one of the most effective and environmental friendly methods for solid waste treatment and energy utilization. Application of this method for the treatment of the sewage sludge is presented here. A literature review on the status of sewage sludge treatment and plasma gasification progress is included here, with a view to identify the potential of the application of the plasma gasification process for the utilization of sewage sludge. For that purpose, results from two detailed studies concerning process design for plasma gasification of sewage sludge produced in the Athens’ Central Wastewater Treatment Plant, Greece, are presented here, with a focus on the differences of the main products obtained, that is, electricity and hydrogen. In all cases, it is clearly demonstrated that plasma gasification of sewage sludge results in net production of significant amount of energy, along with a nonhazardous solid residue by-product, that is, vitrified slag, with various end-use applications.