This study was designed to examine the underlying structure of the Children’s Playfulness Scale (CPS). The CPS was administered to 602 children who were randomly divided into two groups (calibration and validation group). The calibration group (n= 279) included 137 boys and 142 girls, and the validation group (n= 323) included 162 boys and 161 girls, ranging in age from 4 to 6 years. A one-factor model was postulated and supported. According to the model, 5 variables measuring children’s playfulness loaded on one factor (playfulness). In addition, the proposed model was found to be invariant across the two groups. Good cross-generalizability of the CPS appears to support its validity. Educators working in a preschool/kindergarten setting may use it with confidence when evaluating children’s playfulness.