Appropriate use of non-conventional water resources including surface runoff and sewage is produced an issue that has emerged as a necessity particularly in Iran. This thread has been created specifically in Tehran. The current study was aimed to investigate the economic value of sewage at Agricultural Sector in South of Tehran with produced approach in the contaminated and clean area. From the results, the average yield of wheat production among the farmers from polluted water was 376 kg ha-1 more than farmers who used clean water. Moreover, the economic value of water was 110 Rials more than farmers who used clean water. According to the results, the total value of wastewater in Tehran in 1405 would be equivalent to 335,480 million Rials. The priorities for interests of irrigation using wastewater from an agricultural perspective suggests that availability and reliability of wastewater than other water sources and low cost of its use is the most important benefit. The next priority result of irrigation with wastewater is increasing crop yield and improving soil fertility. This explains why farmers despite the legal prohibition of the use of untreated sewage continue to utilize this source of irrigation water.