Results suggest that the Global Assessment of Functioning (GAF) scale and the Children’s Global Assessment Scale (CGAS) may not reliably measure functioning in children with complex trauma exposure. Clinicians often use the GAF and CGAS to help make decisions about treatment progress, outcomes, and needs. Results suggest variability in clinicians’ reliability, favoring child cases without a history of trauma compared to those with a trauma history. The two most commonly used mental health measures of functioning of traumatized and non-traumatized children are the GAF and the CGAS. Only a limited number of studies have examined the reliability of the GAF and CGAS with child populations. Studies of the reliability of these measures have yielded mixed results. Using clinical case vignettes of both traumatized and non-traumatized children, this study attempted to estimate the reliability of the GAF and the CGAS. Table, references