New Zealand youth who had smoked only one cigarette had diminished autonomy over smoking. We sought to examine this issue in a US sample and examine the early onset of DSM-IV nicotine dependence. A self-administered survey was completed by 367 adolescent smokers in Massachusetts. Diminished autonomy was measured with the Hooked on Nicotine Checklist. Diminished autonomy was present in 5.7% of youth after one cigarette, in 9% after 2, in 26% after 3-4, in 44% after 5-9, in 43% after 10-19, in 67% after 20-99, and in 96% after 100 or more. DSM-IV nicotine dependence was absent in youth who had not smoked 10 cigarettes but was present in 9% after 10-19 cigarettes, in 17% after 20-99, and in 58% after 100 or more. Our data confirm the New Zealand study by showing diminished autonomy among subjects who had smoked only 1 or 2 cigarettes. Diminished autonomy after one or two cigarettes, and DSM-IV nicotine dependence after 10-19, support the sensitization-homeostasis theory of nicotine addiction that the addiction process is initiated by the first few cigarettes.