Experts in traumatology have postulated traumatized children play differently than non-traumatized children. These differences are called posttraumatic play and include the behaviors of intense play, repetitive play, play disruption, avoidant play and negative affect. The purpose of this study is the continued development of the Trauma Play Scale through the addition of a normative sample. The Trauma Play Scale is an observation-based instrument designed to distinguish the play behaviors of children in play therapy with a history of interpersonal trauma when compared to non-traumatized children. The present study compares two samples of children. One group (n=6) currently in play therapy with a history of interpersonal trauma and another group (n=7) considered normally developing (cognitively, emotionally, socially, and physically) by their parents with no known history of interpersonal trauma. Trained raters blind to the trauma history of the children rated a series of eight consecutive video-recorded play therapy sessions for each participant. One-way analysis of variance statistics, including effect sizes were compute to determine the discriminant validity of the Trauma Play Scale. Traumatized children scored significantly higher on the Trauma Play Scale than non-traumatized children on all domains of the scale as well as the overall Average Trauma Play Scale score. Large effect sizes indicated strong relationships between group membership (trauma history versus normally developing) and scores on the Trauma Play Scale.