Bicuspid aortic valve occurs in 0.8-2% of European and North American populations.12 It is the most common reason for a predisposition to severe aortic regurgitation or stenosis in middle life, but patients are asymptomatic until late in the disease. Failure to present until clinical symptoms develop—either because the murmur is not detected or is lost to follow-up—can have important consequences. Early detection and continued surveillance are crucial to allow early intervention and preservation of cardiac function. We describe two patients with heart murmurs diagnosed in childhood who were lost to follow-up. Both presented as adults with heart failure and complications of bicuspid aortic valves. One developed aortic stenosis, the other aortic incompetence. Both needed urgent surgery. Many people in the general population with bicuspid aortic valves have never been diagnosed or have been reassured in childhood and are no longer under review.