Preschool children from Israeli, Jewish-Orthodox families with an average of four children per family drew their families. Three aspects of gender differentiation in children's drawings were assessed in relation to children's gender and number of siblings: size of figures, colour use, and inclusion of gender-associated characteristics. Size of drawings reflected gender differentiation, with fathers being drawn larger than mothers. Boys, and children with more siblings, drew both their mothers and their fathers larger. Colour use did not differ by children's gender or number of siblings. Girls evidenced greater gender differentiation in their drawings, including more gender-associated characteristics than boys, both in their drawings of children, and in their drawings of adults. Finally, children who showed no differentiation between parents in terms of gender-associated characteristics drew both mothers and fathers smaller than children who showed such gender differentiation, and boys who did not use a variety of colours in their drawings drew their fathers larger than their mothers, whereas those who used a variety of colours, drew their parents the same size, indicating that the measures of gender differentiation are related. The results were discussed in terms of children's emerging gender differentiation of self and others in large families.