Analysis of the dichloromethane extract of the aerial parts of Croton cuneatus led to the isolation of the new glutarimide alkaloids: julocrotol (1), isojulocrotol (2), and julocrotone (3) along with the known compounds julocrotonine (4), lichexanthone (5) and selin-11-en-4alpha-ol (6). The structures of the new compounds were established by spectral methods. The in vitro cytotoxic activity of Compounds 1-6 was evaluated against six human tumor cells lines.