This study examined the association between cognitive impairment and anxiety disorders following traumatic brain injury (TBI). Sixty-six participants recruited from a rehabilitation hospital completed the Structured Clinical Interview for the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition) and cognitive tests at one year post injury. Prevalence of anxiety disorder was 27.3%. Logistic regression analyses revealed that the attention/working memory, information processing, and executive functions models were significantly associated with anxiety disorder. The memory model was not significant. Processing speed emerged as the strongest model associated with anxiety disorder. The role of cognitive impairment in the etiology of anxiety disorders after TBI is discussed, and treatment implications are explored.