The consumption of medicinal herbs in Nigeria has seen a notable surge in recent years due to their widespread availability, affordability, and the prevailing belief in the natural and non-toxic nature of herbal treatments.The objective of this research was to examine the potential toxicity of the dehydrated leaf extract derived from Costus afer Ker Gawl on the hepatic and renal systems of male albino Wistar rats. The research used a cohort of 20 male albino Wistar rats weighing between 100 and 170 grams. These rats were placed into four groups, each consisting of five individuals. Group A was provided with unrestricted access to conventional feed and water, and it was designated as the control group. Participants in Group B, C, and D were administered doses of 400, 700, and 1000mg/kg of an aqueous leaf extract derived from Costus afer, respectively. The medication was administered orally on a daily basis for a duration of twenty-one days. The animals were sedated with chloroform vapor and subsequently dissected twenty-four hours following the previous dosing. The kidneys were collected, measured, and preserved in a 10℃ formal saline solution for the purpose of histological examination. Serum preparation included the collection of blood by eye puncture in order to conduct histochemical investigations. The assessment of marker enzymes was conducted using the randox kit methodology. An investigation was conducted to examine the impact of C. afer on the renal biomarkers urea and creatinine. Group D had substantially elevated serum levels of creatinine and urea (P≦0.05) compared to the control group A, as well as groups B and C. In the histological examination, it was shown that Group D of the kidney, which received a dosage of 1000mg/kg of an aqueous leaf extract, exhibited significant renal tissue damage characterized by necrosis, renal bleeding, loss of renal tissue, and deteriorated glomeruli. Costus afer was found to possess alkaloids, saponins, flavonoids, phenolic compounds, and tannins, as indicated by the conclusion. High dosages of Costus afer may be renally toxic.The use of medicinal herbs in Nigeria has seen a notable surge in recent years due to their widespread availability, affordability, and the prevailing belief in the natural and non-toxic nature of herbal treatments.The objective of this research was to examine the potential toxicity of the dehydrated leaf extract derived from Costus afer Ker Gawl on the hepatic and renal systems of male albino Wistar rats. The research used a cohort of 20 male albino Wistar rats weighing between 100 and 170 grams. These rats were placed into four groups, each consisting of five individuals. Group A was provided with unrestricted access to conventional feed and water, and it was designated as the control group. Participants in Group B, C, and D were administered doses of 400, 700, and 1000mg/kg of an aqueous leaf extract derived from Costus afer, respectively. The medication was administered orally on a daily basis for a duration of twenty-one days. The animals were anesthetized with chloroform vapor and subsequently dissected twenty-four hours following the previous dosing. The kidneys were collected, measured, and preserved in a 10℃ formal saline solution for the purpose of histological examination. Serum preparation included the collection of blood by eye puncture in order to conduct histochemical investigations. The assessment of marker enzymes was conducted using the randox kit methodology. An investigation was conducted to examine the impact of C. afer on the renal biomarkers urea and creatinine. Group D had substantially elevated serum levels of creatinine and urea (P≦0.05) compared to the control group A, as well as groups B and C. In the histological examination, it was shown that Group D of the kidney, which received a dosage of 1000mg/kg of an aqueous leaf extract, exhibited significant renal tissue damage characterized by necrosis, renal bleeding, loss of renal tissue, and deteriorated glomeruli. Costus afer was found to possess alkaloids, saponins, flavonoids, phenolic compounds, and tannins, as indicated by the conclusion. High dosages of Costus afer may be renally toxic.