Gender differences in mathematical achievement have been examined in a wide range of age groups but only a few studies addressed this issue in preschool children. We compared preschool girls (n=570) and boys (n=524) from Germany with regard to numerical competencies. Differences in overall group means and the frequency of representation at low, middle, or high levels of performance were explored for girls and boys. Analysis of overall group means revealed that boys showed a better performance than girls (d=.32). The analysis of frequencies showed differences in both tails but not in the middle of the distribution of numerical competencies. While boys were more often found at higher levels of performance, girls were found to be overrepresented in the low-ability end of the distribution. These findings demonstrate that gender differences in mathematical achievement can emerge before school entry and stress the importance of further research looking for gender divides in mathematical achievement in preschool children from different countries as well as possible underlying factors. (author abstract)