This paper evaluates neuroimaging of cognitive control as an endophenotype for investigating the role of dopamine genes in ADHD. First, this paper reviews both data-driven and theory-driven approaches from genetics and neuroimaging. Several viable candidate genes have been implicated in ADHD, including the dopamine DRD4 and DAT1 genes. Neuroimaging studies have resulted in a good understanding of the neurobiological basis of deficits in cognitive control in this disorder. Second, this paper discusses imaging genetics in ADHD. Papers to date have taken one of two approaches: whereas early papers investigated the effects of one or two candidate genes on many brain areas, later papers constrained regions of interest by gene expression patterns. These papers have largely focused on cognitive control and the dopamine circuits involved in this ability. The results show that neuroimaging of cognitive control is useful as an endophenotype in investigating dopamine gene effects in ADHD. Other avenues of investigation are suggested by a combination of data- and theory-driven approaches in both genetics and neuroimaging.