ABSTRACT.During the past two years, we have recorded 45 neonates during extracorporeal membrane oxygenation therapy (ECMO). We have developed methods of minimizing artifacts and obtaining useful recordings in over 90% of cases. Adequate EEG recording of neonates during ECMO therapy is often difficult because of abundant artifacts secondary to the extensive supportive machinery and monitoring systems required for these critically ill patients. The integrity of the central nervous system (CNS) of these infants is often uncertain because of the sedative, paralyzing, and analgesic medications required. The EEG can provide a clue to CNS function. Our methods involve specific electrode application techniques, use of a modified placement and montage, and interruption of unessential electrical fuses and other equipment frequently present in ICU settings. These methods have enabled us to obtain records lengthy enough to include both active and quiet sleep and to eliminate or diminish most artifacts, including ECMO pump artifact.