To assess the effect of beta-blockade therapy on clinical outcome in patients with Marfan's syndrome.Despite the lack of definitive evidence to support its efficacy, beta-blocker therapy is widely used prophylactically in patients with Marfan's syndrome.A meta-analysis was instituted, which included studies identified by a systematic review of MEDLINE of peer-reviewed publications and by abstracts from annual scientific meeting. Outcome measures of mortality and major morbidity were compared between patients treated and untreated with beta-blockade therapy. Data was combined according to both a fixed-effects and random-effects model. The endpoints included aortic dissection or rupture, cardiovascular surgery, or death.Six studies were included, 5 were non-randomized follow-up studies and 1 was a prospective randomized trial (802 patients). Ninety-six of 433 patients treated with beta-blocker therapy and 74 of 369 untreated patients reached designated endpoints. Utilizing a fixed-effects model, patients treated with beta-blocker therapy were more likely to reach an endpoint (odds ratio=1.50 with 95% CI 1.05–2.16). However, by a random-effects model, the treatment effect failed to reach significance (1.54 with 95% CI 0.99–2.40).On the basis of this meta-analysis, there is no evidence that beta-blockade therapy has clinical benefit in patients with Marfan's syndrome.