A blueprint for the ideal anticancer molecule would include most of the properties of nitric oxide (NO*), but the ability to exploit these characteristics in a therapeutic setting requires a detailed understanding of the biology and biochemistry of the molecule. These properties include the ability of NO* to affect tumour angiogenesis, metastasis, blood flow and immuno surveillance. Furthermore NO* also has the potential to enhance both radio- and chemotherapy. However, all of these strategies are dependent on achieving appropriate levels of NO*, since endogenous levels of NO* appear to have a clear role in tumour progression. This review aims to summarize the role of NO* in cancer with particular emphasis on how the properties of NO* can be exploited for therapy.