Alphamethrin is one of the extensively used pyrethroids. Its non-specific mode-of-action might affect the non-target-organisms. Its toxicity data on aquatic organisms are lacking. We determined the toxicity (35 days) of alphamethrin (0.6µg/L and 1.2µg/L) on non-target-organisms by evaluating the efficiency of hematological, enzymological and antioxidants biomarkers of Cyprinus carpio. Compared with the control group, the efficiency of the biomarkers studied was significantly (p<0.05) impaired in the alphamethrin groups. Alphamethrin-toxicity altered hematology, transaminases and the potency of LDH of fish. ACP and ALP activity and biomarkers of oxidative stress in the gills, liver and muscle tissues were affected. IBRv2 index reveals that the biomarkers were inhibited. The observed impairments were the toxicity effects of alphamethrin with respect to concentration and time. The effectiveness of biomarkers for alphamethrin toxicity was like the toxicity data available on other banned insecticides. Alphamethrin could cause multiorgan toxicity on aquatic organisms at µg/L level.Copyright © 2023. Published by Elsevier B.V.