Refuse-derived fuels (RDF) are a category of alternative fuels produced as byproducts from the process of waste management plants. RDF can be utilized for heat and power production, contributing to the waste hierarchy set by European Union. However, the need for standardization of RDF becomes gradually important in South-Eastern Europe, where the market for waste recovered fuels is under development. The application of certification and quality management schemes in the waste treatment and fuel production processes, along with the use of a new terminology, solid recovered fuels may enhance public acceptance and promote the thermal utilization of this resource in industrial facilities. In the present work, a sampling and analysis campaign of RDF produced at a mechanical and biological treatment facility in Athens, Greece, took place. The sampling and analysis were carried out according to the standards of CEN/TC 343. The sampling period lasted 1 year, resulting in 20 samples. Proximate, ultimate analysis, chlorine and heavy metals’ content were carried out. Furthermore, a technical and economic assessment was carried out, in order to propose realistic solutions for the improvement of the produced RDF quality and the plants’ viability. Two sets of scenarios are assessed with techno-economic criteria referring to different technical solutions. At the end of the study, a step-by-step approach is proposed, which may guarantee the economic feasibility of the proposed plant retrofitting project and a pay-back period adjusted to the extent of the retrofitting measures to be decided.