Mercury accumulation affects the gastrointestinal, and renal systems. In this study, we aimed to study the physiological, and histological effects of mercury oxide on the liver and kidney in male Wistar rats. During 22 days, we divided 25 rats into 5 groups. The control group is placed first, followed by vinegar, low, medium, and high dose mercury groups. The control group was given only water. The vinegar-only group was given only vinegar. Mercury oxide-treated (HgO) group was given HgO 0.375 mg/kg/day. Mercury oxide treated group given HgO 1.5 mg/kg/day. Mercury oxide-treated (HgO) group was given HgO 4.5 mg/kg/day. We studied the levels of ALP, LDH, AST, ALT, albumin, creatinine, and urea. Histopathology of the liver and kidney were also studied. The result of this study was hepatic sinusoid dilation, renal tubule degeneration, and glomerulus shrinkage. This study showed non-significant differences among groups in terms of renal glomerulus diameter. The results showed that HgO at dose (1.5 mg/kg/day) had significantly higher levels of LDH, ALT, and AST enzymes when compared to the control group. While at the highest dose of mercury oxide (4.5 mg/kg/day), LDH, ALT, and AST enzyme levels decreased when compared to the lower doses. Our results showed a non-significant increase in urea level. Consequently, our investigation demonstrated that exposure to mercury oxide after therapy may result in toxicity to the kidneys and liver.