OBJECTIVE:The purpose of this study is to establish the test-retest reliability of the Child-Initiated Pretend Play Assessment (ChIPPA) (Stagnitti, 2002a; Stagnitti, Unsworth, & Rodger, 2000). METHOD:The first author rated 38 preschool children ages 4 and 5 years (4 with developmental delay and 34 typically developing) on the ChIPPA. The ChIPPA employs conventional play materials and unstructured play materials to assess three qualities of a child's play ability: elaborateness of play action, ability to substitute objects during play, and the child's need to imitate the modelled actions of the examiner. The ChIPPA was administered twice, at a 2-week interval, to each participant. RESULTS:Test-retest intraclass correlation coefficients (ICCs) (Type 2,1) calculated for each of the three elaborate play measures ranged from .73 to .84. A test-retest ICC of .56 was obtained for object substitution with unstructured play materials. The test-retest ICC obtained for the combined score for unstructured and conventional play materials was .57. Percentage agreement figures ranging from 63.2% to 84.2% were obtained on test-retest of the object substitution with conventional toys and imitated actions measures. There was no significant difference between test and retest scores for these measures based on a Wilcoxon Matched Pairs Signed-Ranks Test (Wilcoxon Sign Test). CONCLUSION:Elaborate play scores, object substitution with conventional toys score, and imitation scores on the ChIPPA showed stability over time. Object substitution scores using unstructured materials were the least stable play measures and appeared to be related to the child's play themes. Since play is the primary occupation of children, it is essential that therapists have a reliable measure of play behavior. The test-retest reliability results from the ChIPPA provide evidence that this assessment produces a stable measure of play behavior that can then guide therapists when planning intervention strategies for children.