Background: Parenteral nutrition (PN) is a complex and costly therapy that places significant demands on healthcare resources. Commercially manufactured 3-chamber bags (3CBs) offer potential time and cost advantages compared with hospital pharmacycompounded bags (HCBs); however, no data are yet available from studies comparing these delivery systems in US hospitals. The primary aim of this study was to evaluate the PN preparation time and resource utilization required for 3CBs compared with HCBs in US hospitals. Methods: A prospective, multicenter, time and motion study was performed to evaluate the time from transcription to completion of PN preparation and costs for 3CBs compared with HCBs. The cost per bag included labor, PN products, medical consumables, and equipment. Results: One hundred thirty-six PN prescriptions were prepared during the study (66 prescriptions for 3CBs and 70 prescriptions for HCBs). The mean ± standard deviation total time required for transcription, review, validation, and preparation of PN was 5.5 ± 1.3 minutes for 3CBs vs 14.3 ± 6.2 minutes for HCBs (P < .001). The mean total cost per PN bag was $81.60 for 3CBs and $131.17 for HCBs (mean difference, −$49.57). Conclusion: Commercial 3CBs reduced staff time by 62% and direct costs by 37% compared with HCBs. The results demonstrate that 3CBs offer potential cost-savings for hospitalized patients who require PN in US hospitals.