To evaluate the potential role of taurine deficiency in the pathogenesis of parenteral nutrition-induced cholestasis, 20 premature (<34 weeks AGA) infants were randomized to receive parenteral nutrition with and without taurine (10.8 mg/kg/day) during the first 10 days of life. Birth weight, gestational age, and protein and caloric intake were similar in both groups. Plasma taurine levels and hepatic function were assessed before the study began (3 ± 1 days of age), at 5 ± 1 days of age, and at 9 ± 1 days of age. Although plasma taurine levels were significantly greater at 5 ± 1 and 9 ± 1 days of age (p = 0.009) in the group receiving supplementation, no differential effect on hepatocellular function could be detected during this short period of time. A decrease in plasma ammonia (p = 0.001), alanine aminotransferase (ALT) (p = 0.036), γ-glutamyltranspeptidase (GGTP) (p = 0.05), 5-nucleotidase (5'N) (p = 0.001), and bile salt concentrations was noted in both groups, indicating the rapid maturation of hepatic function even in the presence of parenteral nutrition during the first 10 days of life.