Wastewater treatment in developing countries is not always sustainable due to the application of inappropriate treatment technologies. Various technological alternatives of wastewater treatment are available ranging from conventional methods to advance treatment methods. Construction of best available wastewater treatment technology is a possible solution for the improvement of environmental impact of the available treatment system (septic tank) for Gish Abay Campus, Bahir Dar University. In this study a MultiCriteria Analysis Decision Making tool is adopted to evaluate different wastewater treatment technologies. A hybrid multiple-criteria decision making model based on the analytic hierarchy process and the technique for order of preference by similarity to ideal solution is proposed as a tool to evaluate and prioritize various wastewater treatment technologies. Wastewater treatment alternatives were evaluated according to economical, technical, environmental and social criteria in which there are ten indicators by equal weight and unequal weight scenarios. Expert responses were used in the selection of wastewater treatment technologies to form different weight matrices. Depending on the priorities of the scenario the alternatives are ranked based on their relative closeness to the ideal solution. The model is finally applied to select best available wastewater treatment technology alternative among three options of sequential batch reactor, up flow anaerobic sludge blanket, and septic tank with horizontal constructed wetland. The result of this study reveal that UASB is best available wastewater treatment alternative. Sensitivity analysis also showed that a very stable ranking with the leading alternative of up flow anaerobic sludge blanket.