This research aims to understand how children conceptualise lying and how they associate it with moral reasoning within a narrative that contains everyday moral transgressions. This study also explores whether children are willing to lie when they are asked to do so by close adults, such as mothers, fathers and teachers, even after declaring that lying is wrong. We interviewed children (N = 146) from first to fourth grade on these themes, and discovered a developmental trend in the concept of lying, which is associated with other moral reasoning dimensions. Most children could define lying in a reasonable and accurate manner, and considered it inappropriate behaviour, but half admitted to lying after a close adult requested it.