The standard model of particle physics describes three massless (anti)neutrinos. 
Experimentally we have established that these neutrinos can oscillate between themselves and thus we know that they actually do have a mass, opening a window to study physics beyond the standard model. Furthermore, there are indications that maybe more neutrino flavours are needed to fully explain all oscillation data, which are dubbed sterile neutrinos. In this talk I will summarize the experimental data leading to the proposal of sterile neutrinos, show the ongoing programs searching for them and the future prospects.