The present study first examined the links between reactive temperament (negative affectivity), regulative temperament (effortful control [EC]) and internalizing problems in adolescents (12-18 years) with anxiety disorders (ANX; N = 39) and without anxiety disorders (nANX; N = 35). Links differed between ANX and nANX participants. Negative affectivity predicted internalizing problems, with almost no role of EC in nANX, but a protective role of EC was found in ANX youth. Second, we investigated the role of attentional bias as a mediator between temperament and internalizing problems. Strategic threat-related bias was predicted by initial attention and EC, but these relations differed in both groups. In nANX participants, higher initial bias scores were predictive for lower strategic bias scores and higher levels of EC were associated with higher bias scores. In ANX participants, there was almost no effect of initial bias or EC on strategic attention. Internalizing problems were predicted by strategic attention, but again differently in ANX and nANX participants. High strategic bias scores were associated with an increase in anxiety in ANX and a decrease in anxiety in nANX participants. (Contains 4 footnotes, 5 tables, and 5 figures.)