Sirtuins (SIRT) are group of enzymes that require nicotinamide adenine dinucleotide (NAD+) to catalyze their reactions. These chemical compounds have mono (ADP-ribosyl) transferase or deacetylases activities, and they can be found in nearly all species. The mammalian sirtuin family is described by seven proteins, namely. Every group of sirtuins can be found in the different regions of the cells ; SIRT1 is predominantly nuclear, SIRT2 is located mainly in the cytoplasm (but it can shuttle between the nucleus and the cytoplasm), SIRT3, SIRT4, and SIRT5 are mitochondrial proteins, (SIRT3 can move from the nucleus to mitochondria during cellular stress), SIRT6 and SIRT7 are nuclear sirtuins. Sirtuins have a lot of functions in different physiological processes such as gene repression, metabolic control, apoptosis and cell survival, DNA repair, development, inflammation, neuroprotection, and healthy aging. Because of so many roles in physiological processes there is a huge interest not just in their functions but also in the different compounds which can modify their functions. In this article we will focus on the role of sirtuins in tumorigenesis.