To assess the safety of moderately early hospital discharge for normal newborn infants (mean +/- SD, 31 +/- 5 hours after delivery), we compared the incidence of hospital readmission within 6 weeks of birth with the incidence of readmission among a similar cohort of infants with extended hospitalization (mean +/- SD, 92 +/- 44 hours) as a result of maternal illness. The hospital charts for all infants admitted to the well-baby nursery between January 1 and December 31, 1985, were reviewed. Fifty-two (3.0%) of the 1714 infants who were discharged moderately early and 17 (2.7%) of the 622 infants who had an extended hospitalization were readmitted to the hospital by age 6 weeks (P = NS). Maternal age, financial status, and race each failed to predict infant readmission. Only four of the 52 readmission diagnoses among infants discharged moderately early could potentially have been identified (not prevented) before discharge with an extended newborn hospitalization. These data indicate that moderately early neonatal hospital discharge does not result in an increased incidence of rehospitalization within the first 6 weeks of life.