To determine the safety, efficacy, and cost savings of early hospital discharge of very-low-birth-weight infants (less than or equal to 1500 g), we randomly assigned infants to one of two groups. Infants in the control group (n = 40) were discharged according to routine nursery criteria, which included a weight of about 2200 g. Those in the early-discharge group (n = 39) were discharged before they reached this weight if they met a standard set of conditions. For families of infants in the early-discharge group, instruction, counseling, home visits, and daily on-call availability of a hospital-based nurse specialist for 18 months were provided. Infants in the early-discharge group were discharged a mean of 11 days earlier, weighed 200 g less, and were two weeks younger at discharge than control infants. The mean hospital charge for the early-discharge group was 27 percent less than that for the control group ($47,520 vs. $64,940; P less than 0.01), and the mean physician's charge was 22 percent less ($5,933 vs. $7,649; P less than 0.01). The mean cost of the home follow-up care in the early-discharge group was $576, yielding a net saving of $18,560 for each infant. The two groups did not differ in the numbers of rehospitalizations and acute care visits, or in measures of physical and mental growth. We conclude that early discharge of very-low-birth-weight infants, with follow-up care in the home by a nurse specialist, is safe and cost effective.