Four bipolar temperament qualities (i.e. extroversion-introversion, practical-imaginative, thinking-feeling and organized-flexible) of 800 South African children, ages 9-10, 11-12, 13-14 and 15-17, first are described and then compared to temperament qualities of 800 US children of the same ages. South African children do not differ in their preferences for extroversion-introversion and more frequently prefer practical to imaginative, feeling to thinking and organized to flexible styles. In contrast to South African boys, South African girls are more likely to prefer extroverted and feeling styles. Two bipolar temperament styles display age changes: practical-imaginative and organized-flexible styles. South African and US children do differ on all four temperament styles. Compared to US children, South African children are more likely to prefer introverted, practical, feeling and organized styles; these differences generally were found between boys and girls from the two countries. Age difference appears on two bipolar temperament qualities between the two countries thinking-feeling and organized-flexible styles. (Contains 2 tables.)