Background: Parenteral nutrition (PN) covering the need for carbohydrates, amino acids, and lipids can either be compounded from single nutrients or purchased as an industrially manufactured ready-to-use regimen. This study compares a commercially available 3-chamber bag (study group) with a conventionally compounded monobag regarding nutrition efficacy, safety, and regimen preparation time. Materials and Methods: This prospective, randomized, single-blind study was conducted at 5 Chinese hospitals from October 2010-October 2011. Postsurgical patients requiring PN for at least 6 days were randomly assigned to receive the study or control regimen. Plasma concentrations of prealbumin and C-reactive protein (CRP), regimen preparation time, length of hospital stay (LOS), 30-day mortality, safety laboratory parameters, and adverse events (AEs) were recorded. Results: In total, 240 patients (121 vs 119 in study and control groups) participated in this study. Changes in prealbumin concentrations during nutrition support Delta(Prealb(StudyGroup)) = 2.65 mg/dL, P < .001 vs Delta(Prealb(ControlGroup)) = 0.27 mg/dL, P = .606) and CRP values were comparable. Regimen preparation time was significantly reduced in the study group by the use of 3-chamber bags (t((StudyGroup)) = 4.90 +/- 4.41 minutes vs t((ControlGroup)) = 12.13 +/- 5.62 minutes, P < .001). No differences were detected for LOS, 30-day mortality, safety laboratory parameters, and postoperative AEs (37 vs 38 in study and control groups). Conclusion: The PN regimen provided by the 3-chamber bag was comparable to the compounded regimen and safe in use. Time savings during regimen preparation indicates that use of 3-chamber bags simplifies the process of regimen preparation.