Chaos in the home is a key environment in cognitive and behavioural development. However, we show that children's experience of home chaos is partly genetically mediated. We assessed children's perceptions of household chaos at ages 9 and 12 in 2337 pairs of twins. Using child-specific reports allowed us to use structural equation modelling to explore the genetic and environmental etiologies of children's perceptions of chaos. We found that these perceptions are significantly heritable (22%), with the remainder explained by environmental influences. Finding that genes influence children's experience of chaotic environments has far-reaching implications for how we conceptualize the family home and its impact on cognitive and behavioural development. (Contains 3 tables.)