Previous studies have demonstrated increased risk-taking in adolescents with Conduct Disorder (CD) compared with typically developing controls. Increased risk-taking may partly mediate the pathway from genetic or environmental risk to CD. We investigated the familial basis of risk-taking by examining whether the unaffected relatives of CD probands (n = 22) showed heightened risk-taking in a gambling task, in common with affected probands (n = 44). Adolescents with CD were more likely to select risky options than the typically developing controls (n = 37) and unaffected relatives. Our findings confirm the association between CD and increased risk-taking, but suggest that this decision-making style may not have a familial basis.