Objective: To present the results of numerous studies that assessed the efficacy, safety and tolerability of venlafaxine extended release (XR) in treating anxiety disorders, particularly generalized anxiety disorder (GAD). Method: Efficacy was assessed with the Hamilton Rating Scale for Anxiety, Clinical Global Impressions scale, Hospital Anxiety and Depression scale and other instruments. Standard safety and tolerability assessments were used. Results: In four placebo-controlled trials, venlafaxine XR was effective and well tolerated in patients with GAD. Several additional smaller studies found venlafaxine XR effective in treating anxiety associated with social phobia, obsessive-compulsive disorder and panic disorder. Conclusion: Venlafaxine XR has both short- and long-term efficacy and tolerability in treating symptoms of long-term anxiety and comorbid anxiety and depression, and in achieving remission in GAD patients. These characteristics, combined with early onset of anxiolytic action and dose-response effect, make it a logical choice for treating anxiety occurring alone or comorbidly with depression.