Purpose-The purpose of this paper is to evaluate the efficiency of a duckweed pond in the polishing of a stabilization pond effluent, as well as quantify its biomass production. Once an adequate destination is given to the produced biomass, the wastewater treatment plant can work in a sustainable and integrated way. Design/methodology/approach-The duckweed pond consisted of a tank with volume 0.44 m 3 , operating in continuous flow with an outflow of 0.12 m 3 /day and hydraulic retention time of 3.8 days. Effluent samples were collected before and after the treatment, with analyzes made: daily-pH, dissolved oxygen and temperature; twice a weektotal nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD); and weeklytotal solids (TS) and Biochemical Oxygen Demand (BOD 5). The duckweeds were collected each for seven days for its production quantification.