Several wastewater treatment plants technologies have been set up in the Egyptian villages; however, the most efficient and economical technology hasn't been determined. This research aims to distinguish between the wastewater treatments plants which are used in rural Egypt to find out the best between them. The data about Centralized and Decentralized wastewater treatment plants which are used in rural Egypt using group of factors has been collected to distinguish between the characterizations of these plants by doing a questionnaire to evaluate the weight of these factors. The questionnaire has been given to experts to evaluate the factors for getting relative weights of them. Expert evaluated the factors according to his importance by choosing a mark from the lowest value one to the highest value ten. After receiving the results of the questionnaire from the experts, the data were processed to find out the best group of results of these plants. The largest percentage of Relative Weights of factors is Efficiency, followed by Costs, Average load removed, Specific surface area, Average flow and Average population. The best three centralized wastewater treatment plants were from the aerobic treatment.