The problem of efficient wastewater treatment is increasingly brought into society nowadays. The pollution effect of insufficiently treated wastewater on surface water is manifested by the content of total suspended matter, organic matter, organic nutrients of nitrogen, phosphorus, ammonium and pathogenic microorganisms. The purpose of this research is to deepen practical and theoretical knowledge to improve the wastewater treatment process. Research period: January-June 2021, the object of study is the Wastewater Treatment Plant in Chisinau. In order, to monitor the technological process of wastewater treatment, five main indicators are checked daily: acidity (pH), temperature (T), biochemical oxygen consumption (BOD), chemical oxygen consumption (COD), total suspended solids (TSM), as well as the content of organic nutrients (N, P). Of these quality indicators, only the pH and temperature fall within the norms of reception-discharge of wastewater, the rest of the indicators do not correspond to the norms recommended for the reception and evacuation of wastewater. However, the Wastewater Treatment Plant in Chisinau is in the process of reconstruction with special normative evacuation facilities, coordinated with the State Ecological Inspectorate of Republic of Moldova. Considering that an efficiently functional wastewater treatment plant has a certain treatment capacity for the above mentioned indicators that do not fall within the prescribed norms: BOD-70-90%, COD-70%, TSM-90%, NH4 –N- 70-80%, P-80%, from the obtained results the treatment capacity of the treatment plant is: BOD-78%, COD-64%, TSM-70%. The nutrient content of wastewater before and after treatment indicates that in the Chisinau Wastewater Treatment Plant are discharged wastewater with increased loads of pollutants, which exceed the norms of maximum permissible concentrations, and the treatment capacity is lower: NH4-N- 27-34%, P-78%. Based on these data, we can conclude that the treatment plant has a satisfactory treatment capacity, although the treatment capacity is reduced due to the reconstruction works and the increased concentrations of pollutants received in the wastewater.