Treatment of neonatal jaundice is phototherapy with blue light at wavelength about 460 nm and irradiance > 30 uw/cm2/nm. Though, recent in vitro models have suggested that a wavelength of 478 nm should be optimal in reducing total serum bilirubin. The aim of this study is therefore to compare the efficiency of phototherapy with light emitting diodes (LED's) of 478 vs. 459 nm., respectively.