Objective To place imaging–genetics research in the context of child psychiatry. Method A conceptual overview is provided, followed by discussion of specific research examples. Results Imaging–genetics research is described linking brain function to two specific genes, for the serotonin-reuptake-transporter protein and a monoamine oxidase enzyme. Work is then described on phenotype selection in imaging genetics. Conclusions Child psychiatry applications of imaging genetics are only beginning to emerge. The approach holds promise for advancing understandings of pathophysiology and therapeutics.