Overall response rates of clofarabine-based rescue regimens in relapsed or refractory acute leukemia range from 17-48%. In our study, response rates, infection-related complications and side effects were evaluated after salvage therapy with clofarabine-based regimens in patients diagnosed with relapsed and/or refractory acute leukemia. Twelve patients who received clofarabine-based rescue therapy in our clinic between January 2015 and December 2020 were evaluated retrospectively. Fifty-eight percent of the patients were male and the mean age was 36.6±16.4 years. Seventy-five percent of the patients had a diagnosis of acute lymphoblastic leukemia, 25% had a diagnosis of acute myeloid leukemia. A median of 3 cycles of chemotherapy was given before clofarabine. Sixty-six percent of the patients were followed as refractory to the last treatment, and 33% as early relapse. Patients received intravenous treatment between 1st and 5th days at a dose of clofarabine 22,5 mg/m2 +cytarabine 1000 mg/m2 . During the treatment, all patients were complicated with febrile neutropenia, 58% of them developed sepsis. Serious (grade 3-4) non-hematological side effects were hepatotoxicity in 33%, diarrhea in 25%, nausea and vomiting in 16%, and mucositis in 16%. Neurotoxicity related to clofarabine was not observed. One of the patients achieved complete response (8%), 33% of the patients were unresponsive. The mortality rate within the first 30 days was 50% (n = 6). Early death (<2 weeks) occurred in one of the severe patient. For patients with refractory or early relapse acute leukemia, the main goal is to progress to allogeneic bone marrow transplantation after salvage therapy. Although complete remission can be achieved with bone marrow transplantation, 4-year survival does not exceed 25-30%. Therefore, a powerful and effective salvage treatment regimen is still needed in patients with relapsed or refractory acute leukemia.