Prime volume of the cardiopulmonary bypass circuit may lead to significant hemodilution and the potential need for blood products for all patients, but may be more critical in the pediatric and, specifically, the neonatal patient. We report on the first use of the Terumo CAPIOX FX05 (Baby-FX) oxygenator with integral arterial filter, prime volume 43 ml, evaluating performance and air-handling of six Baby-FX versus thirteen Baby-RX oxygenators. The Terumo Baby-FX primes and performs as easily as the Baby-RX series. A significant prime component in the neonatal CPB circuit can be the arterial line filter (ALF). Removal of the ALF may lead to significant reduction in prime volume, decreased exposure to foreign surfaces with subsequent reduction in inflammation, and potential elimination or reduction in blood product exposures.