"The Play Therapy Skills Checklist (PTSC) is an instrument used primarily in the training, supervision, and research of child centered play therapy; however, reliability procedures have not yet been conducted. This study represents the first psychometric exploration of the instrument through the establishment of inter-rater reliability lending validity to the application of PTSC in play therapy research. A free marginal multi-rater kappa was computed to check the reliability of raters' categorization of play therapy responses. The resulting kappa of .82 indicates that the raters categorized play therapy responses in a similar form. The intra-class correlation coefficient (ICC) indicates that the inter-rater reliability for the play therapists' ratings of play therapy response categories was .95, indicating high levels of inter-rater reliability. Our results indicate a strong agreement between the raters and the categories listed in the PTSC. It is recommended that researchers continue to explore the test-retest reliability, as well as other validity procedures."