Objective: According to the attention network approach, attention is best understood in terms of three functionally and neuroanatomically distinct networks—alerting, orienting, and executive attention. An important question is whether the experience of emotion differentially influences the efficiency of these networks. Method: This study examines 180 participants were randomly assigned to a happy, sad, or control condition and undertook a modified version of the Attention Network Test. Results: The results showed no effect of happiness or sadness on alerting, orienting, or executive attention. However, sad participants showed reduced intrinsic alertness. Conclusion: This suggests that sadness reduces general alertness rather than impairing the efficiency of specific attention networks. (J. of Att. Dis. 2010; 13(6) 629-639)