The purpose of this study was to establish the validity, reliability, and utilization of a revised and expanded Preschool Health and Safety Knowledge Assessment (PHASKA), an instrument evaluating health and safety knowledge of young children, on a diverse group of preschool children. Methods: This study included 308 children (133 boys and 175 girls) ranging in age from 28 to 80 months (M = 53.7 months). The PHASKA was administered to children at 6 preschools and 5 health fairs on an individual basis. Results: Scores on the PHASKA ranged from 1 to 49 (out of a possible 50 points), with a mean score of 37.25. Ninety-seven percent of the children older than age 3 years completed the assessment. No significant differences attributable to gender were found. However, significant age group differences were found [F (7, 300) = 31.09, P