Identifying and intervening with youths who may be prone to misconduct and aggression is an important management task in institutional settings. Psychopathy, typically assessed via the Psychopathy Checklist—Revised (PCL—R) or Psychopathy Checklist: Youth Version (PCL:YV), has been asserted to be a prominent predictor of acting out among youths, even in controlled environments such as detention facilities or psychiatric hospitals. The present study investigated this association meta-analytically by aggregating effect sizes for three types of institutional misconduct (total, aggressive, physically violent) across 15 samples (N = 1,310). The weighted mean correlations ranged from .24 to .28, although there was considerable heterogeneity for aggressive and physically violent misbehavior. The file drawer problem was reflected in the variability in aggressive misconduct, with published studies reporting larger effects (weighted r = .33) than unpublished reports (weighted r = .14). Moreover, this difference could not be explained in terms of differing methodological quality between published and unpublished studies. Failure to consider the totality of the extant research may lead to inflated perceptions of the predictive utility of juvenile psychopathy measures in institutional settings.