The construction of reinforced concrete structures in aquatic systems and water basins has now become an inevitable need. Concrete structures, both simple and large, such as retaining walls, the design of landscape areas, bridges, hydroelectric power plants, and dams affect water basins. These structures contribute positively to mankind but the negative impact on the aquatic environment is inevitable. The present study determined the toxic effects of various concrete elements, such as cement (C), cement/set accelerating admixture (CS), cement/plasticizer (CP), and all additives (CSP) on rainbow trout (Oncorhynchus mykiss) cultivated in freshwater. The negative control group was devoid of additives. The mortality rates reported for these additives were 5, 20, 35, and 45%, respectively. Negative control groups were not associated with mortality. In addition, histological examination revealed severe toxic symptoms and effects on gills, liver, kidney, and spleen of fish.