The twigs, leaves, and flowers of Hyptis tomentosa were found to owe their major cytotoxic activity to the presence of desoxypodophyllotoxin (4), but the two weakly cytotoxic flavones 5-hydroxy-4',6,7,8-tetramethoxy flavone (3) and 5-hydroxy-4',3,6,7,8-pentamethoxy flavone (2) also contributed to