Studies conducted in Ukraine on the long-term oncological consequences of the Chornobyl disaster indicate a significant impact of radiation after an emergency exposure on the incidence of malignant neoplasms of the affected population. This is evidenced by the increased radiation risk of leukemia in liquidators, which exceeds the national population level and its value is comparable to the data on atomic bomb survivors. For the first time in this cohort the radiation dependence of chronic lymphoid leukemia was established. There are radiation risks of leukemia in children exposed to the Chornobyl exposure. There is an increase in the incidence of thyroid cancer not only in children but also in adults: liquidators, evacuated from 30-km zones and inhabitants of areas contaminated with radionuclides. There is an excess of breast cancer in women-liquidators. The incidence of all forms of malignancy compared to national rates decreases over time, but still exceeds them. It is expected that further monitoring of malignant neoplasms in the groups of victims will allow to quantify the radiation risks of already known from previous studies of forms of cancer and those whose radiation-associated manifestation can be expected in the future. Key words: Chornobyl catastrophe, victims, malignant neoplasms, leukemia, breast cancer, thyroid cancer.