Outcomes of a follow-up, preventive care program based on a self-regulation model of neonate and parent behavior were studied in a controlled experiment. Subjects included a preterm control group, preterm intervention group, and full-term control group, with each group consisting of 27 infants. The assessment, which used the Brazelton Neonatal Behavioral Assessment Scale, focused on ways in which infants regulated behavior in the newborn period. At four weeks and at four months (corrected age), parents kept a diary for one week in which they recorded the times when the infant was asleep, awake and happy, or awake and miserable. During the newborn period of the self-regulation model, the task for the infant was to return to base or physiological stability. Parent responses indicated that the challenge for the infant was to achieve quiet states and that premature infants had more difficulty than full-term infants in achieving that goal. The intervention was designed to set appropriate limits that would enable the infant to achieve a still body for quiet sleep and calm awake time. Limits on motor interference and extraneous stimuli were set. Results indicated that by one month, premature infants in the intervention group slept at regular times, on average, 72 percent of the time. Parents worked with infants to achieve a rhythm of returning to base. Premature infants were able to effectively use awake time at four months, if the time was limited to 1.5 to 2.5 hours and sleep occurred regularly. (RH)