Callao Bay is strategically important for the industrial and tourist sector, serving as a recreational space for a large part of the population of Chalaca. However, even so, it permanently receives discharges of effluents, chemical products, and residues from oil refineries, hydrocarbons, and domestic and agricultural residues. The objective of this research is to evaluate biochemical indicators in fish against contaminants in the coastal area of Callao, Peru. The seasonal criterion (collections in autumn, spring, summer, and winter) and the spatial criterion (collections at four points along the coastal zone of Callao) were considered. Isacia conceptionis and Odontesthes regia showed relatively high concentration values of the enzyme alanine aminotransferase (ALT). Specifically, ALT is an enzyme used to assess liver function. Sciaena deliciosa showed high levels of alkaline phosphatase (ALP) in the liver but low values of aspartate aminotransferase (AST) and ALT. In addition, ALP is an indicator of renal impairment; in saltwater fish, its increase may be related to the increase in water salinity. The fish with the highest trophic level among the marine fish analyzed was O. regia. This fish presented the lowest values of ALP in the liver and muscle ALP and AChE (acetylcholinesterase) in the liver and the highest values for AST. S. deliciosa and O. regia are species that can be used in environmental biomonitoring, showing variation to the biomarkers studied because they have shown changes in the values of biochemical markers, mainly AChE of the brain and muscle, and in the protein concentrations of muscle, brain, and liver between seasons and sampling points in Callao Bay. It is concluded that the marine fish models evaluated are very useful in assessing contamination in Callao Bay.