AIM: There is increasing concern about the behavioural and cognitive effects of watching television in childhood. Numerous studies have examined the effects of the amount of viewing time; however, to our knowledge, only one study has investigated whether the speed of editing of a programme may have an effect on behaviour. The purpose of the present study was to examine this question using a novel experimental paradigm. METHODS: School children (aged 4-7 years) were randomly assigned to one of two groups. Each group was presented with either a fast- or slow-edit 3.5-min film of a narrator reading a children's story. Immediately following film presentation, both groups were presented with a continuous test of attention. RESULTS: Performance varied according to experimental group and age. In particular, we found that children's orienting networks and error rates can be affected by a very short exposure to television. CONCLUSION: Just 3.5 min of watching television can have a differential effect on the viewer depending on the pacing of the film editing. These findings highlight the potential of experimentally manipulating television exposure in children and emphasize the need for more research in this previously under-explored topic.