Anxiety disorders are highly prevalent and disabling disorders, for which selective serotonin reuptake inhibitor (SSRI) antidepressants are an effective treatment. Escitalopram is the most selective SSRI available. Beyond its well-established efficacy in depression with or without anxiety, preclinical studies have demonstrated that escitalopram has a broad spectrum of anxiolytic activity. This review focuses on the therapeutic use and the tolerability issues of escitalopram in the treatment of adult patients with panic disorder, generalized anxiety disorder (GAD), social anxiety disorder, and obsessive-compulsive disorder (OCD), on the basis of numerous recent short-term and long-term controlled studies in these disorders. In a 10-week randomised, double-blind trial in patients with panic disorder, escitalopram (flexible doses 5-10 mg/d) was significantly more effective than placebo in reducing the panic attack frequency, with a faster onset of action than citalopram. Fifty percent of escitalopram recipients and 38% of placebo recipients experienced no panic attacks, with a similar incidence of the most common adverse events for both groups. LITERATURE FINDINGS IN PD: In an open-label study in elderly (>65 years) patients with panic disorder, improvement in panic attack frequency and secondary efficacy variables occurred more rapidly in escitalopram than citalopram recipients. LITERATURE FINDINGS IN GAD: In four double-blind, comparative, eight- to 12-week studies in patients with GAD, escitalopram was more effective than placebo and at least as effective as paroxetine in reducing the mean Hamilton Rating Scale for Anxiety total score. Escitalopram 10-20 mg/d demonstrated continued efficacy in a 24-week extension study of short double-blind trials and in a placebo-controlled, double-blind, 24/76-week relapse-prevention study. In this trial, escitalopram recipients showed a significantly longer time to relapse and reduced risk of relapse than placebo recipients, and the risk of relapse was 4.04 times higher in the placebo group than in the escitalopram group. Escitalopram was well tolerated and only 7% patients withdrew, due to adverse events in the escitalopram group, versus 8% in the placebo group. LITERATURE FINDINGS IN SOCIAL PHOBIA: In two randomised, double-blind, 12- and 24-week studies in patients with social anxiety disorder (social phobia), escitalopram 10-20 mg/d was generally more effective than placebo and at least as effective as paroxetine in reducing the mean Liebowitz Social Anxiety Scale total scores. In a 24-week double-blind, placebo-controlled relapse-prevention study, escitalopram recipients had a longer time to relapse and reduced risk of relapse compared with placebo recipients, and significantly fewer escitalopram than placebo recipients relapsed (22% versus 50%). In these studies, the treatment effects of escitalopram were independent of gender, symptom severity and chronicity, and comorbid depressive symptoms, and the drug was tolerated well. LITERATURE FINDINGS IN OCD: Finally, in patients with OCD, escitalopram 20mg/d for 12 weeks was more effective than placebo, and at least as effective as paroxetine 40 mg/day, with respect to a mean reduction from baseline in the Yale-Brown Obsessive Scale total score. In a 24-week, randomised, placebo-controlled relapse-prevention study, the proportion of patients who relapsed in the escitalopram group (23%) was 2.74 times lower than in the placebo group (52%). In both groups, the majority of adverse events reported were mild to moderate. On the whole, numerous clinical data indicate that escitalopram, 10-20 mg/d, is an effective and well-tolerated first-line treatment option for the management of panic disorder, GAD, social anxiety and OCD. Beyond short-term demonstrations of efficacy in these disorders, several controlled relapse-prevention studies showed the necessity and utility of maintaining the treatment six months or more after the remission has been obtained.