Radioactive and chemical contamination can affect carcinogenesis, including the development of malignant neoplasms of the ovaries (MNOs) in women. The study aimed to perform comparative assessment of environmental situation in the towns and districts of the Bryansk Region based on chemical, radioactive, and combined radioactive contamination, as well as primary incidence of MNOs in women in accordance with official statistics for the years 2000–2019. The data for the study were provided by the Bryansk Regional Oncology Dispensary, Bryanskstat, Rostekhnadzor, Rospotrebnadzor. Neither significant differences in primary incidence of MNOs, nor increased risk of MNO were revealed in female population aged 18–80 years, regardless of the environmental conditions of living in 2000–2019. We revealed a significantly elevated relative risk (RR) of primary incidence of low-grade MNOs in women aged 41–60 years living in the environmentally disadvantaged areas compared to women living in the control areas: RR 1.88 (95% CI: 1.43–2.48); p < 0.0001). The rate of low-grade MNOs in women aged 41–60 years in the areas of the combined exposure is 17.6 ± 1.96, which 1.5-fold exceeds the values reported for radioactively contaminated areas (11.7 ± 2.73) and 1.2-fold exceeds the values reported for chemically contaminated areas (15.2 ± 1.31). The combined effects of radioactive and chemical contamination results in the higher RR of low-grade MNOs compared to the areas with only one pollution factor, i.e. radioactive contamination (RR 1.51 (95% CI: 1.00–2.28)), chemical contamination  (RR 1.17 (95% CI: 0.90–1.50)). The findings suggest synergistic effect of radiation and chemical factors on the incidence of low-grade MNOs.