There is increasing interest to administer ibuprofen as a continuous infusion instead of a traditional bolus for treating Patent Ductus Arteriosus (PDA). However, its compatibility data with commonly used drugs in the neonatal period, including parenteral nutrition (PN) and lipids is unavailable. The aim is to determine the compatibility of intravenous ibuprofen lysine with various ANZNN parenteral nutrition consensus group standard neonatal PN formulations and lipids. The PN and lipid solutions used in a tertiary neonatal unit were obtained. These included a Starter, Standard Preterm and low carbohydrate PN, and IV SMOF lipid admixture (SMOFLipid 20% 15 mL; Vitalipid N infant 4 mL, Soluvit N 1 mL) plus vitamin mixtures. 10% glucose was used as a control. 1:1 mixtures of different concentrations (1.25 to 5mg/mL) of ibuprofen lysine and each of the PN/glucose/lipid formulations were made. Samples were taken at hourly intervals for a total of 4 hours and tested for both physical (visual assessment, pH and microscopy) and chemical compatibility (High Performance Liquid Chromatography analysis). Zeta potential and particle diameter were measured for SMOF lipid admixture and ibuprofen combination to assess emulsion stability. 24 hour stability of ibuprofen dilution in 5 mL BD Luer-lok polypropylene syringes at 25°C was also assessed. Most PN formed opaque solutions when mixed with ibuprofen 2.5 and 5mg/mL solutions. However, ibuprofen dilution of 1.25mg/mL produced clear, colourless solutions with no microscopic particles when mixed with all PN/glucose/lipid formulations tested. Ibuprofen was chemically stable with all PN and SMOF lipid admixture, for a period of 4 hours. The zeta potential and particle diameter were within acceptable limits. Ibuprofen lysine was stable over 24 hours in Luer-lok polypropylene syringes. Ibuprofen 1.25mg/mL is physically and chemically compatible with 10% glucose, starter PN, standard preterm and low carbohydrate PN, and SMOF lipid admixture plus vitamins for a period of four hours, which is the maximum time they could be in an admixture during a continuous infusion.