Oral mucositis, characterized by ulcerative lesions in the oral mucosa of patients undergoing chemotherapy, is currently considered to be the most severe complication of anti-cancer therapy which is affecting 40-80% of those patients. Ankaferd hemostat, (ABS) is the first topical hemostatic agent regarding the red blood cell (RBC)-fibrinogen interactions tested in the clinical trials. ABS also has pleiotropic effects particularly in the tissue healing and has anti-infective properties. The aim of this study is to assess the safety and efficacy of ABS in the management of chemotherapy-induced oral mucositis in adult patients with hematological malignancies. ABS was topically applied to the patients with grade 3-4 mucositis according to the WHO classification. Patients were said to mouthwash and swallow the five milliliters of ABS. Twenty patients with oral mucositis were evaluated. Eleven patients with acute myeloid leukemia, four acute lymphoblastic leukemia, three non-hodgkin lymphoma, one hemophagocytosis with acute myleoid leukemia and one hemophagocytosis were included in study. Median extract amount was calculated as 74.50 ml (30-100 ml) and median healing time was 6.6 days (3-10). Consequently, ABS is an effective agent in the treatment of chemotherapy related severe oral mucositis in patients with hematological malignancies. Further experimental and clinical trials about ABS shall focus on the interrelationships between proteomic content, fibrinogen gamma, and vital erythroid aggregation due to ABS.