Orienting responses to visual and auditory stimuli were compared in 3 cohorts of preterm infants born between 1977 and 1987. The sample consisted of 128 infants born between 1977 and 1979, 129 infants born between 1980 and 1983, and 94 infants born between 1984 and 1987. The sample was divided into one group of 140 infants born between 25- and 34-weeks gestation age, and one group of 211 infants born between 35- and 37-weeks gestational age. Ratings were made of orienting responses to a bulls-eye, rattle, bell, voice, and combined face and voice; the orienting items were adapted from the Neonatal Neurobehavioral Assessment Scale. For the 25-to-34-week group, there was a significant difference between cohorts on orienting to rattle, with performance increasing for the more recently born infants. There were significant differences between cohorts in the 25-to-34-week group on orienting to bulls-eye, rattle, and face plus voice. For the 35-to-37-week group, there was a difference between cohorts on orienting to bulls-eye. The infants were assessed when they were medically stable (mean age, 18 days). These results demonstrate a significant change in auditory and visual orienting for preterm infants between 1977 and 1987. The fact that most significant changes were observed among the younger, higher-risk preterm group suggests that medical improvements have resulted in improved outcomes for preterm infants. (RH)