The Child and Young Adult Supplement of the National Longitudinal Survey of Youth (CNLSY) has been used extensively within criminology. A significant amount of criminological research, for example, has explored various issues related to the correlates, causes, and consequences associated with levels of self-control and delinquent involvement. The overwhelming majority of these CNLSY studies, however, have not accounted for the potential effects of genetic factors on these two widely studied criminological variables and thus the findings generated from previous empirical work may be inaccurate due to genetic confounding. The current study partially addresses this possibility by analyzing a sample of kinship pairs nested within the CNLSY. Analyses of these data revealed that genetic factors accounted for between 51% and 92% of the variance in levels of self-control and between 30% and 41% of the variance in delinquency. We discuss the implications of these results for interpreting findings from the large body of existing research using the CNLSY.