Resumo. This study aimed to contribute to the sustainability of pig farming in the state of Santa Catarina, Brazil by proposing to use Lemna minuta as a bioremedy and bioindicator of wastewater. The efficiency of Lemna minuta was tested in different concentrations of ammonia nitrogen. The experiment was executed in five tanks with 5 liters each, that were feed with 2 liters of wastewater from the treatment processes in different concentrations: 100% of wastewater (Lemna 1); 75% of wastewater (Lemna 2); 50% of wastewater (Lemna 3); 25% of wastewater (Lemna 4) and the last received 100% of distilled water (Lemna 5), added floating macrophytes.. The results show that the macrophytes in the tanks Lemna 3 and 4 had better development, achieving the greatest growth and biomass formation, besides the best removal of nutrients from the liquid environment. The best overall performance was in a range of concentration of ammoniacal nitrogen between 20mg.L e 50 mg.L, the best removal efficiency was of 60% (Lemna 3). To the orthophosphate, the best remotion was 51% (Lemna 4). The increase in oxidized nitrogen indicated the nitrification and nitration process. Lemna minuta shows potential as a bioremediation for water suffering from the impact caused by pig farming, so a bioindication of pollution of this type.