The paper presents application of multicriteria analysis for selection of the best technology of a small wastewater treatment plant. The calculations performed for two plant capacities and various effluent standards are based on compromise programming method. For each plant’s capacity the three different treatment technologies are considered. The selection of the best technology is done with a define set of sustainability criteria. The proposed method can be used for selection of the best treatment technology and the technical solution at the stage of wastewater system planning and designing as well as for evaluation of already operated plants from sustainability standpoint.