A survey of current detention criteria reveals considerable variation, depending on the degree of adherence to the 'parens patriae' philosophy. Under the parens patriae view, criteria are deliberately vague in order to allow predictive judgments to promote treatment. The due process model considers only community safety or a child's physical welfare. Guidelines established by the National Council on Crime and Delinquency in 1961 form the legal grounds for detention in most jurisdictions. The guidelines recommend detention of juveniles who are likely to run away during the case processing period, present a danger to themselves or the community, or must be held for another jurisdiction. In contrast, recent guidelines of the Institute of Judicial Administration/American Bar Association Juvenile Justice Standards Project outline strict conditions which would severely limit detention. The authors evaluate the impact of nonlegal factors on detention decisions, including seriousness of offense, number of previous offenses, race, sex, social class, family background, and school problems. Organizational variables in detention decisions include characteristics of decisionmakers, court philosophy, and relationship of the detention facility to other parts of the juvenile justice system. Criteria for a proposed decisionmaking model must agree with the short-term, limited scope of detention; eliminate prediction of future behavior by detention personnel; and emphasize specific, ascertainable events or behavior. The model groups 16 criteria into 5 categories: potential dangerousness to persons or property, risk of flight, previous jurisdiction, necessity for subsequent court processing, and protection of the child. Separation of police power and parens patriae is a major advantage of this model and should encourage a shift to nonsecure detention for juveniles. The paper contains 115 footnotes.