Bioassay-guided fractionation of Machaerium multiflorum yielded the hitherto unreported (+)-trans-hexahydrodibenzopyrans machaeriol A (1) and machaeriol B (2), as well as the known guaiane sesquiterpene (-)-kessane. Structure elucidation was based on (1)H and (13)C NMR data, mainly 2D NMR (1)H-(1)H