This study was performed to determine whether covering the eyes with an opaque screen over the head end of the bassinet instead of the normal patch would improve the behavioral organization of jaundiced, but otherwise healthy, term infants treated with phototherapy. 38 matched infants were randomly assigned to have a patch or a screen. Serum bilirubin at the time of observation was 11.2-17.5 mg/100 ml (mean = 13.7, patch) and 9.4-16.4 mg/100 ml (mean = 13.4, screen). 19 infants, of whom 11 were jaundiced (6.2-14.3 mg/100 ml, mean = 10.3), served as control subjects. The infants were examined with the Brazelton scale on the 3rd day after birth, when the patch subjects had been under blue light from 6 to 45 h (mean = 23.9), and the screen subjects from 6 to 61.5 h (mean = 22.6). The control subjects scored better (all differences, p less than 0.05) than the patch subjects on inanimate visual, animate visual, visual and auditory, alertness. The control subjects also did better than the screen subjects on inanimate visual, animate visual, animate auditory, visual and auditory, alertness, but poorer on motor maturity and consolability. The screen subjects did poorer than the patch subjects only on skin color lability. At 1 month of age, 9 sets of matched infants were examined. The only difference was that the control subjects did better than the patch subjects on animate visual and lability of state. Our data confirm the poorer short-term orientation performance of jaundiced infants treated with phototherapy but do not indicate that covering the eyes with an opaque screen improves behavioral organization.