Life cycle assessment (LCA) is a powerful environmental quantification tool that can be used to measure the environmental impacts of a product system or process. This study was conducted with the aim of evaluating the wastewater treatment system of Zabul Industrial Town using the life cycle assessment method. The stages of life cycle assessment include four stages that were addressed based on ISO 14040 and ISO 14044 standards. For this purpose, first the input and output data of the system, which include materials, energy and pollutants, were determined.The data required for this research include the measured values of wastewater (such as BOD, COD, pH, chloride, etc.) before and after treatment, as well as materials and energy consumption (electrical energy) for wastewater treatment in one year, and was studied.Then the analysis stage was done with the help of SimaPro software and using ReCePi and Cumulative Energy Demand (CED) methods. The functional unit in this research is one cubic meter of treated wastewater. Environmental consequences were analyzed in 18 groups of mid-level index results using the ReCiPe 2016 Midpoint(H) method and 3 groups of end-level index results using the ReCiPe 2016 Endpoint(H) method. Then the environmental consequences were quantified and analyzed after data normalization. The results obtained from the analysis of the effects index at the intermediate level showed that the greatest environmental effects resulting from the wastewater treatment of Zabul industrial town are respectively related to the consequences of human carcinogenic toxicity (50%), the toxicity of the fresh water ecosystem of (13%), the toxicity of the marine ecosystem (10%) and also the consequences of overnutrition of water ecosystems Shirin and the loss of fossil fuel each have (8%) in the next ranking of environmental effects. Based on the sensitivity test, the most important factor affecting the results was the COD amount, which with a 10% decrease from its initia