Ficus deltoidea Jack leaves extract (FDLE) is rich in phytochemicals like alkaloids, phenolics, flavonoids, and steroids. These phytochemicals possess an excellent potential for medicinal applications. This study aimed to assess the kidney toxicity of FDLE through in vitro and in vivo methods. FDLE was obtained by maceration in methanol at room temperature for 24 h. The in vitro toxicity of FDLE at 10 -100 µg/mL was evaluated in Baby Hamster Kidney (BHK)-21fibroblast cells using the MTT assay method. The in vivo toxicity was assessed by histopathological examination of the kidneys of Wistar rats following oral acute administration of FDLE at 1.250 mg/kg, 2.500 mg/kg, and 3.750 mg/kg twice daily for 14 days. In vitro toxicity tests showed no toxic effect of FDLE on BHK-21 fibroblast cells. The percentage cell viability of BHK-21 fibroblast cells was higher than 60% at all the concentration of FDLE tested, and the IC50 value was 71.63 µg/mL. The histopathological analysis revealed no significant difference in the haemarrage and necrosis observed in the tissues of the kidneys of rats in the FDLE treated groups compared to the control group. Therefore, it could be concluded that FDLE demonstrated no toxic effects in vitro and in vivo, and may be relatively safe when administered to humans.