The authors compared correlates of admission for 100 patients older than 18 years and 100 patients younger than 18 evaluated in a psychiatric emergency service. Stepwise linear logistic regression analysis identified a combination of variables that best predicted the odds of hospitalization for each group. For adolescents, these variables, in order of importance, were suicidal tendencies, physical abuse, a primary diagnosis of schizophrenia, age, and number of suicide attempts. For adults, the variables were delusions, aggressive behavior, suicidal tendencies, and a primary diagnosis of schizophrenia or affective disorder. The authors discuss the implications of these findings for acute psychiatric treatment of adolescents.