Due to the scarcity of natural sources of fish feed in Bangladesh, especially in the Khulna district, tannery and poultry byproducts are predominantly used as a cheap fish feed source in fish culture. The chemical composition of these byproducts may theoretically increase the accumulation of toxic contaminants such as lead, cadmium, and chromium in cultured fish, posing a potential risk to food safety. This study focuses on measuring heavy metal concentration in fish feed and fish to evaluate its possible health risks. Three heavy metals (Cr, Pb, Cd) were determined in nine fish feeds and three fish species (Labeo rohita, Oreochromis mossambicus, and Pangasius pangasius) that were collected from three local markets (Phultala, Daulatpur, and Rupsa) of Khulna, Bangladesh. Heavy metals were determined by acid digestion followed by graphite furnace atomic absorption spectrophotometry (GF-AAS). The concentration of Cr in fish is above the acceptable limit and the concentration of Pb, except in Labeo rohita of Daulatpur, is above the acceptable limit (1 mg/kg) according to WHO. The Cd concentration in fish feed was found in the range of 1.120 ± 0.006 to 3.520 ± 0.005 mg/kg, which exceeded the EU maximum permissible limit. The Target Hazard Quotient (THQ) value of Pangasius pangasius in Phultala is greater than 1, which indicates a significant health threat through long-term consumption. However, in most of the cases, the estimated daily intake (EDI) value for Cd is beyond the recommended value of 0.06, indicating a potential health risk. The Carcinogenic Risk (CR) values for Pb and Cr exceeded the unacceptable limit (10-4), raising concerns about the potential cancer risk associated with the intake of Pb and Cr through the consumption of fish species. This study suggests implementing continuous monitoring of fish-feed-producing companies and local markets through an Environmental Management Framework (EMF) established by the government.