Currently, deacetylated chitin (chitosan) nanoparticles (CNPs) are successfully utilized in aquaculture practices. This trial demonstrates the effi cacy of CNPs in combating diazinon (DZN) toxicity in African catfish, Clarias gariepinus, via monitoring hepato-renal function, serum immune trait, hormonal function, and hepato-renal antioxidant activity. Four groups were allocated as follows: a control group, a CNPs group (0.66 ml/L CNPs), a DZN exposed group (0.598 ppm, 1/10 LC50), and a DZN + CNPs group(0.598 ppm DZN + 0.66 ml/L CNPs), all for 30 days. Exposure to 0.598 PPm DZN resulted in a severe decline in the immune parameters (albumin, globu lin, immunoglobulins (IgG, IgM), and total proteins), neurological indicator, acetylcholinesterase (AchE), reproductive hormones (Testosterone (T.) and Lute inizing Hormone (LH)), and the superoxide dis mutase (SOD) and total antioxidant capacity (TAC) readings in both hepatic and renal samples. Moreo ver, a clear increment in hepatic and renal indicators