The possibility of incorporating carbon-based nanomaterials into living systems has opened the way for the investigation of their potential applications in the emerging field of nanomedicine. A wide variety of different nanomaterials based on allotropic forms of carbon, such as nanotubes, nanohorns and nanodiamonds, are currently being explored towards different biomedical applications. In this review, we discuss the recent advances in the development of these novel nanomaterials for cancer therapy. A comparison between the characteristics, the advantages, the drawbacks, the benefits and the risks associated with these novel biocompatible forms of carbon is presented here. © 2008 Informa UK Ltd.