This study aimed at examining the spectrum and frequency of symptoms of ecstasy dependence and their correlation with psychopathology by controlling polysubstance use in Taiwanese adolescents. Two hundred adolescents who had used ecstasy were recruited into this study. Symptoms of ecstasy dependence that had occurred in the preceding year were determined by an interview using the Kiddie epidemiologic version of the Schedule for Affective Disorders and Schizophrenia. The adolescents' psychopathology was examined using the Symptom Checklist-90-Revised Scale. The proportion of participants who had symptoms of ecstasy dependence was calculated. The association between the number of symptoms of ecstasy dependence and psychopathology was examined by using stepwise multiple regression analysis. The results indicated that "continuing ecstasy use despite knowledge of having a problem related to ecstasy use," "spending a great deal of time in activities related to ecstasy use or to recover from its effects," and "ecstasy use tolerance" were the 3 most prevalent symptoms of dependence, and "withdrawal" was the symptom least reported. Heavy ecstasy use led to more symptoms of ecstasy dependence than light use. Symptoms of ecstasy dependence independently increased the risk of severe psychopathology after controlling the effects of polysubstance use. The results of this study indicated that adolescents were aware of the adverse effects of ecstasy use and that repeated ecstasy use would result in dependence on it. Screening the dependence symptoms of adolescent ecstasy users may help clinicians more thoroughly understand their psychopathology.