Thirteen new limonoids, dysoxylumosins A-M (1-13), along with six known analogues (14-19) were isolated from the twigs of Dysoxylum mollissimum. Their structures were established on the basis of spectroscopic data analysis. Compounds 1-6, 8, and 12 exhibited significant inhibitory activities against human and/or mouse 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). Dysoxylumosin F (6), the most potent substance isolated, showed an IC₅₀ value of 9.6 ± 0.90 nM against human 11β-HSD1.