Data from the National Child Development Study have been used to examine the relationship between mother's smoking during pregnancy and neonatal mortality, birthweight and the subsequent development of the child to the age of 11. In this paper analyses are reported which extend this work to examine development by the age of 16. After allowing for a wide range of related background factors, it is found that mothers smoking during pregnancy continues to be related to the child's reading and mathematics attainment. For boys, but not girls, there is an association with height. An inconsistent relationship is found with the child's history of asthma and wheezy bronchitis. Some doubts about the direct causality of such relationships are discussed.