Phytochemical study of Acanthus arboreus resulted in the isolation of three novel alkaloids: 6-hydroxy-benzoxazolinone, 4-hydroxyacanthamine and acanthaminoside. In addition, a new acyl flavonoid apigenin-7-O-beta-D-(6-trans-p-coumaroyl)-3-O-acetyl glucopyranoside was also isolated. The known compounds were identified as apigenin, apigenin-7-O-beta-D-(6-trans-p-coumaroyl)glucoside, vanillic acid, lupeol, stigmasterol and sitosterol glucoside. The structures were determined by physical, chemical and spectral techniques.