Provides a review of laboratory and performance-based assessment techniques that have been used in research with children who have severe conduct problems. Many of these techniques have proven useful for monitoring the effects of interventions, which seems to be their most immediate clinical use. With further development, several of these techniques have the potential for assessing clinically important processes that may be involved in the development and maintenance of conduct problems in youth, especially processes that may differ across subgroups of children with conduct disorders (CDs). The assessment of such processes could contribute to the development of individualized treatment plans for children and adolescents with CDs. However, a number of theoretical, methodological, and ethical issues limit the clinical utility of these laboratory and performance-based techniques in their current stages of development, especially in their contribution to making initial diagnoses of CDs. These limitations lead to very cautious recommendations for their clinical use.