Personality traits and most anxiety disorders are strongly related. In this article, we review existing evidence for ways in which personality traits may relate to anxiety disorders: 1) as predisposing factors, 2) as consequences, 3) as results of common etiologies, and 4) as pathoplastic factors. Based on current information, we conclude the following: 1) Personality traits such as high neuroticism, low extraversion, and personality disorder traits (particularly those from Cluster C) are at least markers of risk for certain anxiety disorders; 2) Remission from panic disorder is generally associated with partial "normalization" of personality traits; 3) Anxiety disorders in early life may influence personality development; 4) Anxiety disorders and personality traits are usefully thought of as spectra of common genetic etiologies; and 5) Extremes of personality traits indicate greater dysfunction in patients with anxiety disorders.