, the present study was aimed to explore the possible potential effect of geranium essential oil (GEO) on profenofos (PFF)-induced hepato- renal toxicity, immunosuppressive effects, and oxidative stress in common carp, Cyprinus carpio (L.). A static 96-h acute toxicity test was conducted to determine the 96-h LC50 of PFF in common carp and it was found to be 46.34 µg L-1 calculated by Finney probit analysis. One hundred and twenty fish were randomly allocated into four groups in triplicate. The first served as control and second groups were fed on basal diet that was enriched with 0.0 and 400 mg kg-1 of diet GEO, respectively without PFF exposure. The third and fourth groups were fed on the same diets and in additions, were exposed to 1/10 of the 96 h-LC50 of PFF (0.0046 mg L-1), respectively. The exposure period lasted for 40 days for all groups during which the liver and kidney function tests, lipid profile, serum proteins, oxidants/antioxidants biomarkers, and immunological parameters were estimated. As well as histopathological examination of liver and kidney and immunohistochemical staining of caspase-3 and bcl-2 were applied. The results revealed that the PFF exposure induced marked increases in levels of serum alanine and aspartate aminotransferases (ALT and AST) alkaline phosphatase (ALP), lactate dehydrogenase (LDH), creatinine, urea, cholesterol, triglycerides (TG), and malondialdehyde (MDA) values. Meanwhile, the serum total protein (TP), globulins, glucose, lysozyme activity, complement3 (C3), nitric oxide (NO), and hepatic antioxidant enzyme activities and the reduced glutathione (GSH) content were significantly declined in the PFF-exposed fish compared to the control group. Additionally, vacuolation, pyknosis, and degeneration of hepatocytes and epithelial cells of renal tubules with mononuclear cells infiltration were observed. A strong caspase-3 and weak bcl-2 immunohisto-reactivity in the liver and kidney tissues of PFF-exposed fish were noted respective to the control. Interestingly, GEO supplementation improved these variables with nearly restoring to control values with improving the histological architecture of liver and kidney tissues. The apoptotic condition of the examined tissues was markedly restricted in the combination group than PFF-exposed group. These results concluded that GEO has ameliorative influence against toxic impacts of PFF on hepato-renal functions, immunological parameters and oxidative stress in common carp, and therefore, may serve as valuable dietary additive in aquaculture.