Cooperation and competition are both essential elements of economic life. Here we explore how cooperativeness in a prisoner’s dilemma is correlated with competitiveness in a sample of 9-12 year old children in Colombia and Sweden. Using two different measures and four different tasks for competitiveness, we find no consistent relationship between cooperativeness and competitiveness. However, we find evidence of a negative relationship between willingness to compete in a math task and cooperativeness in the overall sample. Competitiveness in math has previously been related to educational choices, and may therefore be the most economically relevant relationship.