The housing conditions of children in the National Child Development Study are related both to 16-year school attainment and also to progress through secondary school from 11 to 16. Children in homes which are crowded or lacking amenities, or in council homes at sixteen have relatively low scores on tests of reading and mathematics at the same age. The relationship between 16-year attainment and housing conditions is shown to be similar whether the child experienced the unsatisfactory housing at the age of 7, 11 or 16. Crowding and amenities are shown to be slightly associated with progress through the secondary school, although tenure is more strongly associated. The overall conclusions from this study are that children who have ever lived in unsatisfactory housing perform relatively poorly at school when they are 16, but no evidence emerged that there is any particular age at which housing circumstances are crucial for eventual school attainment. Consideration is also given to the importance of the wider environment in which the child lives.