The purpose of this research was to evaluate the level of nicotine dependence (ND) and to examine its association to psychiatric disorders in a representative clinical sample of adolescent psychiatric inpatients. The modified Fagerstrom Tolerance Questionnaire (mFTQ) was used to assess the level of ND. Psychiatric DSM-IV diagnoses were obtained by using the Schedule for affective disorder and schizophrenia for school-age children (K-SADS-PL). Of the total of 342 inpatients in the study sample, 259 (75.7%) reported to be current smokers. A sum score 6 or higher in the mFTQ, indicating a high level of ND, was found in 37.9% of all smokers. An increased likelihood for high level of ND was associated with substance related disorders (OR 5.1, 95% CI 2.8-9.3), conduct disorder and oppositional defiant disorders (OR 2.4, 95% CI 1.4-4.4). The usefulness of mFTQ in measuring ND among adolescent inpatients is apparent. Therefore, it can be recommended to be used as a routine screening instrument for ND among adolescents hospitalized due to psychiatric disorders.