This study compared the approach to neonatal care in Wales and Washington State, studying the extent of perinatal regionalization, the distribution of neonatal technologies, and birthweight-specific neonatal outcomes. In Wales, most District General Hospitals (DGH) had all the neonatal equipment recommended for a maximal neonatal intensive care unit, whether or not the DGH was a designated regional or subregional center. Sophisticated neonatal technology in Washington was concentrated in designated referral hospitals. Almost every Welsh DGH cared for infants weighing less than 1,000 grams at birth, while in Washington State most very-low-birthweight neonates were born in referral centers and the few born elsewhere were transferred immediately after birth. Despite differences in the extent of regionalization, birthweight-specific neonatal mortality rates were similar in the two countries.