¹Department of Pharmacy, Faculty of Health Sciences, Jenderal Soedirman University, Purwokerto, 53122, Central Java, Indonesia DOI : 10.29228/jrp.517 The anti-inflammatory properties of Jatropha curcas leaves have been established. The Acute toxicity test showed that J. curcas leaves were safe. This study aimed to assess the safety of the ethanol extract of J. curcas (EJC) leaves on hematological indicators and renal function. In the present study, using 40 male and 40 female Wistar rats were conducted to evaluate subacute toxicity. The EJC leaves with doses of 150, 300, and 600 mg/kg BW, were given orally and repeated for 30 days. The result showed no mortality and no changes in red blood cells (RBC) and white blood cells after administration of EJC leaves, but it caused toxic gastrointestinal symptoms such as a dark and watery stool. The use of the EJC at a dose of 150 mg/kg BW was safe because there was no change in the serum creatinine level and only the tiniest number of dark-stools toxic symptoms was experienced. Histopathologically, the EJC caused necrosis and congestion at doses of 300 and 600 mg/kgBW, which suggests that renal toxicity has already occurred. In conclusion, the EJC leaves with a dose of 150 mg/kg BW were found to be safe on hematology parameters and renal function. In conclusion, the administration of EJC leaves at a dose of 150 mg/kg BW was proven to be safe for renal function and hematological parameters. Keywords : Jatropha curcas, toxicity, subacute, renal, hematology