This study investigated the effects of oral mercuric chloride (HgCl2) treatment on sexually mature albino rats.Different doses of HgCl2 (i.e., 1/4th and 1/8th of LD50, or 5.25 mg/kg and 10.5 mg/kg respectively) were administered to the rats for 30 and 60 days. The results demonstrated a significant dose and duration dependant increase in serum Alanine transferase (ALT), Alkaline phosphatase (ALP), Aspartate transferase (AST), serum bilirubin, urea, uric acid, creatinine, and Blood Urea Nitrogen (BUN) concomitant with a decrease in serum protein levels. Histopathological examination revealed pronounced liver damage, characterized by sinusoidal dilation, necrosis, and fibrosis, as well as marked kidney injury, evidenced by glomerular and tubular damage. The animals also showed a significant rise in lipid peroxidation levels (MDA levels) with a decrease in reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD). Immunohistochemical analysis revealed a decrease in B Cell lymphoma (Bcl-2) expression in the liver indicating apoptotic activity and an increase in Epidermal growth factor regulator (EGFR) expression in the kidney suggesting a compensatory mechanism for tissue repair and regeneration. The study underscores the need for strict regulatory measures to minimize mercury exposure and protect public health.