Background: Seventy percent aqueous methanolic extract of the leaves of Lantana montevidensis exhibited antibacterial, anti-inflammatory, anti-pyretic, antioxidant, and analgesic activities. Previous phytochemical study of the leaves led to the isolation of various flavones, pentacyclic triterpenoids, β-sitosterol and benzoic acid. Materials and Methods: The 70% aqueous methanolic extract of L. montevidensis (Spreng.) Briq. leaves was partitioned between water and n-hexane, CHCl3, EtOAc, and n-BuOH, successively. By using a series of different chromatographic techniques, the CHCl3 and EtOAc extracts afforded nine compounds. The isolated compounds were identified by spectroscopic techniques and by comparison with literature values and/or authentic samples. The free radical scavenging activity of some of the isolated compounds was evaluated. Results: Hispidulin-7-O-glucurnoide methyl ester (1), hispidulin-7-O-glucoside (2), cinaroside (3), nepetin-7-O-glucoside (4) pectolinarigenin (5), apigenin (6), luteolin (7) in addition to salicylic acid (8) and β-sitosterol-3-O-glucoside (9) have been isolated. Compounds 1-4 are first report from the genus Lantana, whereas compounds 5, 8 and 9 are first report from this plant. The structures of these compounds were elucidated on the basis of spectral methods, including 2D nuclear magnetic resonance experiments, and confirmed by comparing with the literature data and/or authentic samples. Additionally, some of the isolated flavonoids exhibited free radical scavenging activity. Conclusion: L. montevidensis (Spreng.) Briq. cultivated in Egypt is rich in biologically active ingredients.