Background: In recent years, scientists have found that certain natural compounds have significant potential in cancer prevention and early-stage cancer treatment. Flavanones, a class of polyphenolic compounds found in plants, vegetables, seeds, fruit peels, and flowers, have been identified to possess anticancer, antioxidant, anti- inflammatory, and antibac terial bioactivities. Cancer has become a major global challenge in terms of both economic and public health concerns. Global statistics indicate that 22.8% of deaths are attributed to non-communicable diseases, and 16.8% are caused by cancer, accounting for one in four and one in six deaths, respectively. Aim : To investigate anticancer effects of Iris Tenuifolia-derived flavanone on cancer cell lines. Materials and Methods : The study was conducted at the Bio-Medical Research Institute of the Mongolian National Uni versity of Medical Sciences, investigating the effect of flavanones on cancer cell viability under in vitro conditions using the MTT assay. In the study, colon, liver, and lung cancer cells were cultured, stabilized, and used for the experiments. Colorectal cancer cells (MC38), liver cancer cells (HepG2), and lung cancer cells (A549) were revived, cultured, and stabilized for use in the experimental procedures. Statistical analysis of the results was performed using Microsoft Excel 2010, and graphs were generated using GraphPad Prism 8. Differences between groups were analyzed using Student’s t-test, and a p-value of <0.05 was considered statistically significant. Results : We treated MC38, HepG2, and A549 cancer cells with different concentrations of flavanone (2.5 µM, 5 µM, and 10 µM) for 24 to 48 hours to evaluate cell viability. Flavanone inhibited A549 cell viability by 2.5 μM-10%, 5 μM-25%, and 10 μM-38%, respectively. For HepG2 cells, flavanone treatment at concentrations of 5-10 µM reduced cell viability by 28–58%. No statistically significant effect on the viability of MC38 cells was observed following treatment with fla vanone at concentrations ranging from 2.5 to 10 µM. Additionally, although MC38 inhibited cell viability in a dose-de pendent manner in cell cultures, it had a statistically significant effect at higher concentrations of 30-200 μM (p<0.01). Conclusion Flavanone inhibits the cancer cell viability in a dose and time dependent manner