BACKGROUND: Renal ischemia-reperfusion (IR) related acute kidney injury (AKI) is an important health problem and has not yet been fully treated. Tarantula cubensis extract (TCE) is a homeopathic drug that has antiinflammatory and antioxidant effects. This study aimed to investigate the effects of TCE on renal ischemia-reperfusion injury in rats. METHODS: This study was carried out on 48 Spraque-Dawley male rats, which were divided into six groups. The first, second, and third groups were control, sham, and IR groups, respectively. Group four received IR and 0.2 mL of 96% ethanol. Group five and six received ischemia and reperfusion and TCE 0.01 and 0.1 mg per rat (which correspond to approximately 0.04 mg/kg, and 0.4 mg/kg), respectively. Tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1ß), total antioxidant status (TAS), and total oxidant status (TOS) levels in renal tissue were measured by enzyme-linked immunosorbent assay (ELISA). Oxidative stress index (OSI) was obtained by proportioning TAS and TOS. Superoxide dismutase (SOD), myeloperoxidase (MPO) activities, and malondialdehyde (MDA) levels were determined by manual spectrophotometric methods. The histopathological changes were evaluated via hematoxylineosin and immunohistochemical staining. RESULTS: In IR group, renal tissue TNF-α and IL-1ß levels were significantly higher than control group (p < 0.0001 for both), and low(p < 0.0001 for both) and high dose (p < 0.0001 for both) TCE administration decreased these markers. Low and high doses of TCE decreased OSI values compared with IR group (p = 0.04 and p = 0.001 respectively). Although TCE decreased MDA levels, it was not statistically significant. MPO levels significantly decreased. In addition, TCE has been found to prevent hemorrhage, cast formation, and dilatation caused by IR in renal tissues stained with hematoxylin-eosin. And also, the most intense nuclear factor kappa B (NFκB) and caspase-3 immunopositivity found in IR group was decreased in both of the TCE groups. DISCUSSION: Although TCE showed a protective effect by inhibiting inflammation against IR damage in renal tissues, there was no clear effect on oxidative stress. Larger and more detailed studies are needed to clarify the issue.