This study examined gender differences in the early mathematical skills of children at risk of developing mathematical difficulties. Of a total sample of 1091 children (49% girls and 51% boys), we observed authentic children who scored low at 33 months with the assessment material MIO (Mathematics, Individual and Environment). Cut-off for low performance was set at the 10th percentile, which gave a larger proportion of boys than higher cut-offs. The results showed no gender differences in the total scores. When distributing the scores into quartiles within gender, there were gender differences in one quartile in favour of the girls. The results showed that two-thirds of the low-performing toddlers were boys.