Mild traumatic brain injury (MTBI) is a serious health problem that has been difficult to study because of the relative insensitivity of established anatomical imaging techniques for detecting the associated neural damage and dysfunction. Functional magnetic resonance imaging (fMRI) offers potential for understanding the neural and functional basis of MTBI and the relationship to behavioral and somatic symptoms. This article reviews the recent fMRI literature relevant to the study of MTBI. The pathophysiology of MTBI and the neural basis of the blood oxygen level-dependent fMRI response are also considered with particular focus on important issues for using fMRI to investigate MTBI.