Despite efforts to operationalize the nicotine dependence syndrome among adolescents, little is known regarding the relative severity of dependence symptoms assessed by different measures. The current study utilized a nonparametric item response model to assess the unidimensionality of the nicotine dependence construct and relative severity of dependence symptoms characterized by the Hooked on Nicotine Checklist (HONC) and the modified Fagerström Questionnaire (mFTQ) in a sample of 109 adolescent smokers (58% female) participating in a prospective investigation of smoking self-change efforts. It was hypothesized that symptoms assessed by the HONC would be associated with lower levels of nicotine dependence severity than symptoms assessed with the mFTQ. Results indicated that HONC and mFTQ items could be linked to a single latent construct. Most HONC items captured variability at the lower range and mFTQ items made discriminations at the middle and higher end of the dependence severity continuum. Findings suggest the HONC and mFTQ may provide complementary information in assessing nicotine dependence levels in adolescent regular smokers and have implications for symptoms expression in youth.