Coumarin enjoys an important place in drug discovery process due to its presence in diversity of
biologically active compounds. Many compounds of plant origin are derivatives of coumarin. Taking these natural
products as lead, research groups across the globe have designed and synthesized numerous coumarin analogues
for treatment of varied diseases. Cancer is one of the dreadful chronic diseases, and many drugs are available for
its treatment. However, due to heterogeneity of cancer, the search is still on to develop drugs for specific types of
cancers. The present review is an attempt to study various coumarin derivatives of natural as well as synthetic
origins, which are identified or developed for the treatment of different types of cancers. Herein, we have
classified various anticancer coumarin derivatives on the basis of their origin as well as substitution around it.
These are discussed under the headings of natural, semi-synthetic and synthetic coumarin derivatives. The
synthetic coumarin derivatives are further classified as mono-, di- and poly-substituted and fused coumarin
derivatives. Of the six positions available for substituents on coumarin nucleus, only three positions (C-3, C-4 and C-7) are exploited for the
selection of functional groups appropriate for anticancer activity. The other positions (C-5, C-6 and C-8) are either unexplored or very
less exploited. The present review is expected to provide the medicinal chemists a guide to choose new functional groups for substitution
at different positions of coumarin nucleus for development of novel compounds for the treatment of a specific type of cancer.