Mercuric chloride (HgCl₂) is a highly toxic form of mercury and a harmful environmental pollutant. This study investigated the protective effects of Turbo cornutus visceral extract against the damaging impacts of HgCl₂ exposure on growth rate, blood parameters, and histopathological changes in various organs of rats. Turbo cornutus is a sea snail species whose visceral extract is composed of a variety of antioxidants and could be easily available for the treatment of the harmful effects induced by mercuric chloride. In this study, 40 male rats were randomly divided into 4 groups (10 rats per 2 cages): control group (G1), group ingested with 200 mg/kg of T. cornutus visceral extract (G2), group exposed to 1/20 of the LD₅₀ dose of HgCl₂ (G3), and the last group was toxic plus treatment group (G4) receiving the same doses as G2 and G3. After 5 weeks of feeding, the rats were euthanized, and the results were recorded. The T. cornutus-treated rats (group 2) showed stable measurements compared to the control group (G1). Exposure to HgCl₂ resulted in alterations in growth rate, blood parameters, and histopathological changes, including Kupffer cell enlargement in the liver, renal tubular damage, and heart edema. However, the administration of Turbo cornutus visceral extract reduced the HgCl₂-induced damage and preserved the integrity of the organs. The obtained results demonstrate the protective effects of Turbo cornutus visceral extract against HgCl₂-induced toxicity in rats. The antioxidant properties of the extract may contribute to its ability to mitigate the harmful effects of mercuric chloride exposure. Further studies are needed to elucidate the underlying mechanisms and explore the potential therapeutic applications of T. cornutus visceral extract in heavy metal toxicity management.