The phytochemical investigation of the dichloromethane extract of the leaves from M. garrettii led to the isolation of the four known neolignans magnolol (3), honokiol (4), 4′-methylhonokiol (5), and obovatol (6) together with two new dimeric substituted neolignans, garrettilignans A (1) and B ( 2). Extensive NMR and MS analyses of the isolated compounds and their acetylated derivatives (1a and 2a) allowed the unambigous structural assignment of these two neolignan derivatives.