Objective: This study aimed to test the effect of an irrelevant external distracter included in a computer-administered visual search test. Two hypotheses were tested: (a) If the distracter affects performance, attention efficiency will be lowered; (b) if children do not habituate to the distracter, performance will be lower for every item of the test. Method: Distraction was induced changing the screen color unexpectedly several times in each trial—450 children (225 girls and 225 boys) from second to sixth course were tested. This group was compared with a group of 423 children from the same age range who were tested with the same test without distraction. Results: Induced distraction reduced attention efficiency for all ages and for every trial in the treatment group (test with distraction). Speed was lower, but number of errors did not increase. Conclusion: School-age children cope with an irrelevant external distracter by reducing speed, not accuracy. (J. of Att. Dis. 2013; XX(X) X-XX)