Curcuma longa has been mentioned in the Indian system of medicine for the management of a wide range of diseases. C. longa and its metabolites like curcumin, ar-turmerone, methylcurcumin, demethoxy-curcumin, and bisdemethoxycurcumin have also been reported to be beneficial in various types of cancer. Curcumin elicits anticancer properties chiefly by triggering apoptotic pathways in cancer cells. The properties are facilitated through diverse signaling pathways viz. pathways mediated by NF-kB, WNT/β-catenin pathway COX-2, LOX, STAT3, prostaglandin E2, phosphorylase kinase, VEGF, AKT, AP1, STAT3, PI3K, Akt, mTOR, ERK5, AP-1, TGF-b, PPARc, EBPa, NLRP3 inflammasome, p38MAPK, Nrf2, Notch-1, AMPK, TLR-4, etc. The present article highlights curcumin biosynthesis, phytochemistry and diverse molecular pathways involved in regulating several types of secondary messengers to exhibit anticancer activity in almost all the forms of cancer.