Functional MRI (fMRI) allows cognitive processes to be studied on an individual basis. fMRI is at the crossing of many fields, such as physiology, MRI physics, cognitive neurosciences, data analysis,.... Hence, it requires the collaboration of inter-disciplinary teams, in which neuroradiologists should play an important role. This article provides an overview of the general principles necessary to conduct fMRI studies on a practical matter (choice of magnetic field, patient set-up and preparation, paradigm design, data acquisition and analysis).