Attention of 43 healthy and 4 hyperactive preschool children was studied by electrodermal activity on 10 passive and active tone listening tasks. On the passive task from Trial 1 to Trial 10, habituation of skin conductance response (SCR) amplitude occurred in the healthy and 2 of 4 hyperactive subjects. The healthy younger subjects, however, should have exhibited significantly greater habituation than the healthy older subjects. The younger children were believed to have a lower attention span. In the remaining 2 hyperactive subjects no SCR was observed on Trials 2 to 10. Habituation of SCR amplitude did not occur during the active task in the healthy and 1 of the hyperactive subjects. The healthy children seemed to have paid more attention during the active task than during the passive task. In 1 of the hyperactive subjects no SCR was observed during the 10 Trials. For the remaining 2 hyperactive subjects, during Trials 1 to 10, a decrease was observed, but none for the healthy subjects. Hyperactive children were believed to have shorter attention spans.