The promise of neuroimaging as an aid to diagnosis is discussed, and findings from the most accessible imaging techniques are reviewed. In addition, some of the earliest findings from functional MR imaging and other technologies are presented with several illustrations. Strategies for interpretation, critique of imaging techniques, and review of major findings for brain injury, mood, anxiety, schizophrenia, and attention deficit disorders are offered. Examples of normal and pathologic images illustrate actual cases and examples of the newer imaging technologies.