Objective: The present study investigated differences in attentional networks in typically developing (TD) boys and boys with ADHD or autism spectrum disorder (ASD). In addition, we investigated the relationship between networks and the relationship with effortful control (EC). Method: An Attention Network Test was used to assess alerting, orienting, and executive attention in 25 TD boys, 25 boys with ADHD, and 25 boys with ASD. Results: In the absence of warning signals, boys with ADHD performed poorer than other children. In all groups, the orienting and executive control networks and the alerting and orienting networks interacted. Executive attention and EC were unrelated. Conclusion: Results provided evidence of impaired tonic alertness in ADHD and support the idea of functional integration of attentional networks. Finally, findings suggest that the link between EC reports and indices of neural systems involved in the effortful regulation of behavior may not be as unambiguous as previously thought. (J. of Att. Dis. 2013; XX(X) 1-XX)