This study investigated the factor structure and reliability of the Saint Louis Symptom Checklist (SLSCL) with an adolescent sample. An exploratory principal components factor analysis followed by a varimax rotation of 209 male and female adolescents yielded eight conceptually relevant factors. Cronbach's alphas for each of the scales ranged from .45 to .94, with a total scale alpha of .92. Directions for future research are discussed. © 2001 John Wiley & Sons, Inc.