Cordycepin is a nucleoside molecule found in and can be obtained through chemical synthesis and biotransformation. Cordycepin has been extensively studied and has been shown to have antitumour activity. This activity includes effects on the autophagy process and inhibition of the MAPK/ERK and Hedgehog pathways. Ultimately, the inhibitory effect of cordycepin on tumour cells is due to the interplay of these effects. Cordycepin was shown to enhance the therapeutic effects of radiotherapy. There is increasing evidence indicating that cordycepin plays an anticancer role in the treatment of various cancers. The present review aims to provide a clear understanding of the antitumour mechanisms of cordycepin and discuss its present application in the treatment of tumours. This information can be an important theoretical basis and provide clinical guidance for the further development of cordycepin as an antitumour drug.