Scalp EEG is characterised by a limited spatial resolution and by a low sensitivity to generators distant from the cortical surface. In contrast, fMRI is characterised by a good spatial resolution and it is sensitive to signal of deep brain structures. By combining EEG with fMRI, it is possible to detect blood oxygenation level-dependent (BOLD) signal changes related with EEG patterns detected on the scalp: EEG-pattern-associated networks can be detected anywhere in the brain with a good spatial resolution. This chapter gives an introduction to the methodology of EEG-fMRI and summarises EEG-fMRI studies focused on epilepsy-related investigations: EEG-fMRI studies on focal epilepsy, generalised epilepsy and paediatric epilepsy are presented. It concludes with a short overview on EEG-fMRI studies on spontaneous brain activity in healthy subjects.