Studies have shown that the rate at which children take up smoking is still very high, particularly for female adolescents. While some progress has been made in determining the factors related to the initiation of smoking, an issue that still requires investigation is the relationship between early smoking patterns and later smoking behaviour. This paper reports the results of a longitudinal study which examined the continuity between smoking at an early age and later smoking behaviour. The smoking behaviour of a cohort of New Zealand children was followed from age 9 to age 15 years. Results showed that children's smoking pattern at age 9 years was not highly related to their smoking behaviour at age 15. The children most likely to become daily smokers by age 15 were those who had smoked within the last year at ages 11 and 13. It was concluded that the formative period for children's daily smoking at age 15 was from 10 to 13 years of age.