THE BRAIN STEM is an unusual location for a pyogenic abscess. We report a case of a brain stem abscess in a 5-year-old boy with tetralogy of Fallot that was refractory to conservative medical therapy but was cured after a single computed tomographic-guided stereotactic aspiration and appropriate antibiotic therapy. The remarkable features in this case were the extremely large size of the abscess (3.2 cm in diameter), occupying the full vertical extent of the brain stem and containing 15 ml of pus. We believe this is the first report of a favorable outcome in a cardiogenic brain stem abscess. The value of computed tomographic-guided stereotactic surgery in the management of this lethal condition is documented with a review of the relevant literature.