Objective: To examine the impact of early discharge on newborn metabolic screening. Study design: Metabolic screening results were obtained from the Alabama State Lab for all infants born at our hospital between 8/1/97, and 1/31/99, and were matched with an existing database of early discharge infants. An early newborn discharge was defined as a discharge between 24 and 47 hours of age. Metabolic screening tests included phenylketonuria (PKU), hypothyroidism, and congenital adrenal hyperplasia (CAH). Early discharge and traditional stay infants were compared to determine the percentage of newborns screened and the timing of the first adequate specimen. Results: The state laboratory received specimens from 3860 infants; 1324 were on early discharge newborns and 2536 infants in the traditional stay group. At least one filter paper test (PKU, hypothyroidism, and CAH) was collected on 99.2% of early discharge infants and 96.0% of traditional stay infants (P < .0001). Early discharge infants had a higher rate of initial filter paper specimens being inadequate (22.9%) compared with traditional stay infants (14.3%, P < .0001) but had a higher rate of repeat specimens when the initial specimen was inadequate (85.0% early discharge vs 75.3% traditional stay, P = .002). The early discharge group was more likely to have an adequate specimen within the first 9 days of life (1001, 98.8% early discharge vs 2016, 96.7% traditional stay, P = .0005). Conclusions: In this well established early discharge program with nurse home visits, newborn metabolic screening is not compromised by early discharge.