Mosquitoes are the foremost arthropod carriers of infection. As a rule, Culex pipiens, known as a house mosquito, could be a vector of many viruses and infectious diseases. The aqueous methanolic extract of Cordyline terminalis Kunth. leaves (syn. Cordyline fruticose) was examined against Culex pipiens Linnaeus (Diptera: Culicidae) to detect its insecticidal activity. Assessing Cordyline terminalis Kunth larvicidal activity against C. pipiens 3rd instar larvae at 24 and 48 hours after application. The results displayed larval mortality after 24-h and 48-h, with LC50 values of 268.96 and 248.43 ppm, respectively. The aqueous methanolic extract and its fractions (petroleum ether, chloroform, ethyl-acetate, and n-butanol) have been demonstrated to exhibit an inhibitory effect against the breast cancer cell line (MCF)-7, liver cancer cell line (HepG)-2, and colon cancer cell line (HCT)-116. The aqueous methanolic extract displayed the most potent cytotoxic activity against the tested cell lines, with IC50 of 9.02, 10.9, and 11.13 µg/mL, respectively. The cytotoxic activity of petroleum ether exhibited IC50 of 9.28, 11.4, and 11.85 µg/mL, respectively. A total of 76 compounds were tentatively identified in Cordyline terminalis Kunth leaves extract, including 30 flavonoids, 13 carboxylic acids, 7 phenolic acids, 4 steroidal saponins, and other different identified compounds, in both negative and positive ion modes, by using UPLC. Overall, the results indicate that the Cordyline terminalis extract has notable and promising larvicidal and cytotoxic activity which may refer to steroidal saponins and anthocyanins that were detected in the plant