Gender differences in creativity scores of the Wallach-Kogan Creativity Tests were found for a sample of 2476 4th- to 9th-graders from 8 primary schools and 4 secondary schools in Hong Kong. Specifically, girls in the junior high grades excelled boys in verbal flexibility, figural fluency, figural flexibility, figural uniqueness, and figural unusualness. These findings contrasted with previous findings of no gender differences in a norming study of the same instrument carried out eight years before this study. The gender differences were explained in terms of environmental effect and cultural effect.[Copyright of Creativity Research Journal is the property of Lawrence Erlbaum Associates. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/10400419.2010.481522]