Serious congenital heart disease leads to abnormal blood flow through the heart and lungs. This results in an inability to carry enough oxygen around the body which makes patients blue (cyanotic) and severely limits their physical activity. People with cyanotic congenital heart disease are at risk of developing brain abscess. This condition is serious and can lead to death because the abscess causes abnormal brain function. Treatment includes antibiotic therapy to kill the bacteria that cause the infection. In people with a large abscess, an operation to drain the abscess may be carried out. Antibiotic therapy for brain abscess should include drugs that penetrate into the abscess cavity. The drugs chosen should also be matched to the sensitivity of the bacteria obtained from the abscess in laboratory culture. There is no evidence from randomized controlled trials to show the best antibiotic regimen for treating people with cyanotic congenital heart disease who develop brain abscess.