This research was conducted to evaluate water quality using bioindicators. Two places were studied with the influence of wastewater generated from the banana packing plant at EARTH University, and one locality without any wastewater discharge. Information was gathered by sampling macroinvertebrates and sampling water for physical-chemical analyses. The method employed was the BMWP-CR (Biological Monitoring Working Party), which has been adapted to Costa Rica. In the wastewater discharge area, the most representative taxa found were, Tubifex, Oligochaeta and Mollusca, all of them indicators of high organic matter pollution. Based on statistical correlations using the PLS method, between macroinvertebrates and physical and chemical variables, a negative correlation existed between the number of organisms and the ammonium, phosphate, and COD present in water. Therefore, a water treatment is recommended for the banana-packing plant.