The aim of this retrospective study was to assess the safety of dental treatment in pediatric patients with acute lymphoblastic leukema (ALL), and Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL), and to report any complications related to dental treatment during a preventive dental program covering a 4-year period. In this study 74 preventive fissure sealants, 69 fillings and 81 extractions along with periodontal treatment that included prophylaxis and/or scaling were performed on 124 patients with a mean age of 7.00 ± 2.3. The patients were monitored for at least three weeks after the treatment for bleeding, pain, local and/or systemic infection, fever, delayed wound healing or any other complication. Two patients (one ALL and one HL) suffered delayed wound healing after extractions which resulted in the delay of chemotherapy. In three of the patients who were in remission-induction phase of ALL, oral mucositis occurred in the cheek mucosa adjacent to extraction sites and five patients had tooth staining due to the routine use of a chlorhexidine mouthrinse. The healing was uneventful in all other patients. The findings of this study suggest that with special precautions such as adequate hematological values, timing of the intervention and supportive medical care, dental treatment can be safely performed in pediatric patients with hematological malignancies. Schlagwörter: leukemia, lymphoma, dental treatment, tooth extraction, periodontal therapy