Introduction. Gingival enlargement is reported as a consistent symptom, which forwards patients for a dentistry consultation and may lead to an early diagnosis of acute leukemia (AL). The objectives of researches were the evaluation of diagnosis and management of hyperplastic gingivitis (HG) in AL. Material and Methods. Our observational, analytical and descriptive study enrolled 7 patients with AL, who were treated at the Institute of Oncology between 2012-2022. The diagnosis was proved by the bone marrow aspiration (BMA) with cytochemical reactions, tissue biopsy or fine needle aspiration cytology. The immunophenotyping was performed in the selected cases. Results. HG developed in cases with myelo-monoblastic and monoblastic AL. The leukemia patients were admitted to the Institute of Oncology with a history of fatigue, fever, bone pain, gingival bleeding and enlargement identified by stomatologists and family doctors from the consulting centers. ECOG-WHO performance score was 2-3. The intra-oral examination revealed generalized gingival hyperplasia. There were the amounts of plaque and calculus, which did not justify the enlargement degree. The gingiva was spongy and painless on palpation, with solitary sectors of necrosis and mucosal bleeding. Blood count: Hb 66-101 g/l, RBC 2.3-3.7 x 1012/l, WBC 11.3-41.2 x 109/l, PLT 37.0-115.0 x 109/l, blast cells 17-56%. The BMA detected myeloid blast cells (31.056.0%) and monocytes (9.0-14.0%). HG regressed in 5 patients after obtaining the complete (4 cases) and partial (1 case) hematological responses under the combined chemotherapy. Conclusions. HG occurs in AL mostly due to the gingival infiltration with blast cells. HG may regress under chemotherapy and local treatment in patients with complete or partial hematological responses.