Removal of phosphorus and nitrogen from eutrophicated water was carried out by in situ bioremediation. With the addition of Acinetobacter calcoaceticus, 65.0% +/- 4.0% of total phosphorus (TP), 37.0% +/- 4.0% of total nitrogen (TN), 75.0% +/- 7.0% nitrite (NO(2) (-)-N), and 87.0% +/- 4.0% of ammonia (NH(4) (+)-N) were removed. Furthermore, chlorophyll a removal in the inoculated treatments reached 83.7% +/- 1.5%, and algae in the water was basically controlled.