The concentration of Cu, Pb, Zn and As in water, sediment and muscle of Oncorhynchus mykiss from the Tishgo river in the central Andes of Peru were analyzed. The water, sediment and fish samples were collected from 36 sites in three sampling sectors. The analytical determination was performed by flame atomic absorption spectrophotometry. The mean Pb concentrations in the water from the three sampling sectors showed significant differences (p < 0.05) which exceeded the values of the Peruvian standard and the WHO. The mean concentrations of Cu, Pb and As in sediment did not present significant differences(p > 0.05) in the three sectors evaluated. The redundancy analysis (RDA) revealed that the concentrations of As and Pb in water, and Cu, As and Zn in sediment significantly influence the concentration of these elements in the O. mykiss muscle. The mean concentrations of Cu, Pb, Zn and As in the O. mykiss muscle were lower than those established by international regulations. Therefore, the concentrations of heavy metals and As recorded in this study do not represent a threat to the consumption of O. mykiss from the Tishgo river.