Abstract A new 7-methoxy-2-benzoxazolinone dimer named zeaoxazolinone (2), together with four known compounds; 9-Z-hexadecenoic acid (1), 6-methoxy-benzoxazolinone (3), gallic acid (4), and β-sitosterol-3-O-b-D-glucopyranoside (5) were isolated from Zea mays L. roots. The structures of the isolated compounds were established on the basis of UV, IR, 1D, 2D NMR, and MS spectral analyses. The antifungal activity of compound 2 was evaluated. It exhibited potent activity against A. flavus, F. oxysporum, and C. albicans at concentration 10 µg/disc.