This longitudinal study examined factors related to smoking at age 13 and to persistence of smoking from ages 13 to 15 years in a sample (n = 719) of New Zealand adolescents. History of smoking at 9 and 11 years predicted smoking at 13 (odds ratio = 2.8), persistence of smoking from age 13 to 15 (OR = 2.4) and smoking at 15 among those not smoking at age 13 (OR = 2.4). While there were no significant sex differences in pre-adolescent and early adolescent smoking, by age 15 more girls than boys reported smoking. A concern with the immediate negative effects of smoking (taste, smell, feeling ill and feeling silly) as a reason for not smoking at age 13 was inversely related to smoking at age 15 (OR = 0.4). Reasons for smoking at age 13 were not associated with later smoking. Family disadvantage and use of alcohol and other drugs were also associated with later adolescent smoking.