Bioassay-guided fractionation of the methanolic extracts of Vismia baccifera, V. jefensis, and V. macrophylla against human breast, CNS, and lung cancer cell lines resulted in the isolation of a new compound, ferruginin C (1), and seven known compounds, ferruginins A (2) and B (3), vismin (4), harunganin (5), vismione B (6), deacetylvismione H (7), and deacetylvismione A (8), as active constituents. In addition, bivismiaquinone (9) and vismiaquinone (10) were obtained as inactive constituents. The structure of ferruginin C was elucidated by spectroscopic means. Compounds 6-8 were the most active, and the cytotoxic activity of compounds 2-5 and 7 is reported for the first time.