The Hooked on Nicotine Checklist (HONC) is a 10-item screening tool originally developed to assess loss of autonomy over tobacco in adolescent smokers. A smoker's endorsement of any item indicates some loss of autonomy, and the sum of endorsed items indicates the degree to which autonomy has been lost. This study extends the HONC to adult smokers. Self-administered questionnaires were completed by a convenience sample of 1,102 adults who were recruited in their natural environments while observed smoking. Subjects were mostly experienced smokers who consumed a mean of 17.5 cigarettes per day and had smoked an average of 20.9 years. HONC scores ranged from 0 to 10, with a mean of 7.1. The HONC appears to measure a single dimension. Internal HONC consistency was high (alpha = .83), and interitem correlations were low to moderate. HONC scores correlated positively with levels of current and peak lifetime cigarette consumption. The HONC scores of heavy, moderate, and light smokers differed significantly in the expected direction. Subjects with higher HONC scores were more likely to report a shorter duration of abstinence and greater use of pharmacological aids when quitting. The HONC appears to be psychometrically sound in both adolescents and adults. It is a reliable and valid measure of lost autonomy for both novice and experienced smokers, and it allows for comparisons between these populations.