Two hundred forty-six full-term, first-born well infants were randomly assigned to receive well-baby care during their first year in one of four ways: six visits by a physician; three visits by a physician; six visits by a pediatric nurse practitioner (PNP); or three visits by a PNP. One hundred sixteen of the study babies received care in a clinic setting and 130 in a private-practice setting. The adequacy of care rendered was assessed by measurement of gain in maternal knowledge important for competence in child-rearing, level of maternal satisfaction, degree of maternal compliance, and attainment of the health supervision planned. These endpoints were subjected to two-way and three-way analyses of variance to determine if there were differences across the setting, provider, or schedule variables. Essentially no differences were observed in the endpoints measured within settings between providers of care, between visit schedules, or between any of the provider and visit schedule combinations. These results indicate that well-baby care during the first year delivered by PNPs is as adequate as that delivered by physicians and the use of abbreviated visit schedules by either professional does not reduce the adequacy of care.