This study examined the impact of a project-based learning module on young children's scientific practices in urban and Indigenous areas. The module was developed by drawing upon early science standards and research on scientific practices and project-based teaching approaches. Ninety-eight children from northern Taiwan participated. Their average age was 5 years and 7 months, ranging from 4 years and 6 months to 6 years and 5 months. A performance assessment of scientific practices was administered before and after the module. Results of paired sample t tests showed that children improved in overall practices and every sub-practice after taking the module. Both city and Indigenous children performed significantly better on the post-test, as did both the 4- and 5-year-old groups. ANCOVA results indicated no significant difference between urban and Indigenous children in the post-test scores of overall and most sub-practices; the only exception was that urban children had significantly better improvement on doing an experiment. Similar ANCOVA results were found for the 4- and 5-year-old groups; the 4-year-old group had significantly better improvement only on measuring. Results suggest that the module promoted scientific practices of children of different ages and ethnic backgrounds. This study sheds light on evidence-based early science curricula, early scientific practices, and the achievement of educational equity.