Beta-blockers are well documented to prolong life in patients after myocardial infarction (MI), yet patients who also have asthma are frequently and understandably denied this therapy. The authors reviewed the literature (via MEDLINE) for the past 35 years for beta-blocker-induced asthma, and reexamined potential beta-blocker use in the context of NIH guidelines for asthma classification and management. Because beta-blockers can cause fatal or life-threatening asthma, their use should be avoided in moderate to severe persistent asthmatics. Benefits of low-dose beta(1)-blockers (e.g. atenolol 50 mg daily) may outweigh risks in some patients with mild intermittent or well-controlled mild persistent asthma. The authors suggest that further study is needed to verify that low doses of beta(1)-blockers are effective in prolonging life after MI, and that use specifically in mild intermittent or mild persistent asthma per NIH classification is safe.