Many varieties of Bougainvillea glabra Choisy have medicinal and insecticidal activity. This study evaluated biological activity of methanolic extract of leaves of Bougainvillea glabra var. “Variegata” at concentrations of 1,000, 750, 500, 250, and 125 ppm against fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), with n = 25 with three replications under laboratory conditions. Methanolic extract at 13% from dried leaves from a nursery affected the susceptible larval stage of fall armyworm. Number killed ranged from 60 to 85%. The weights of larvae and pupae in all treatments were less than the check. All pupae were malformed and no adults emerged. We concluded that Bougainvillea glabra Variegata has potential to use as a bioinsecticide to control of larvae of insect pests because more than 50% of fall aryworm larvae were killed by all treatments.