Background: Leukemia is a common malignancy in children and occurs when changes in normal cell regulatory processes lead to proliferation of hematopoietic stem cells. Leukemic patients have a higher susceptibility to dental and oral diseases such as mucositis and xerostomia due to damage by chemotherapeutic agents to oral mucosal cells which have a high mitotic index. Objective: To determine the characteristics of leukemia in children with oral manifestations at the Abdoel Wahab Sjahranie Hospital Samarinda which is the main referral hospital in the province of East Kalimantan. Materials and Methods: This research is descriptive with cross-sectional method using medical record data as the subject based on the specified criteria. Data were grouped by type of leukemia, age, gender, nutritional status and oral manifestations. Results: A total of 1,330 cases of Leukemia in 2017-2021 with 12 suitable respondents. There were cases with male gender (58.3%) and 0-5 years of age which were comparable to those of 6-18 years (50%). The type of acute lymphoblastic leukemia was the most common in this study with a frequency of 83.3%. Mucositis (58.3%) was the most common manifestation of people with normal nutritional status (41.7%) and laboratory results stated the average of leukocytes was 45,700/uL, hemoglobin was 10.4 g/dl, and platelets was 117,600/mm3. A total of 66.6% of respondents had received chemotherapy. Conclusion: Oral manifestations can occur due to leukemia or side effects of chemotherapy, the importance of multidisciplinary and comprehensive treatment between pediatricians and pediatric dentists in managing the dental health of leukemia patients.