Chalcones comprise a characteristic framework of 1, 3-diaryl-2-propen-1-one. They have been heralded as promising anti cancer drugs and have received much attention in the field of cancer research and drug development. The cytotoxicity of these potent pharmacophores is attributable to a wide spectrum of biological activities like anti inflammatory, anti proliferative, anti fungal, etc. These anti tumor activities are effectuated through apoptosis, cell cycle arrest, anti tubulin and so forth. This review summarizes the recent developments on anti tumor activity of synthetic and natural chalcones and their detailed underlying mechanisms as reported in the past.