Plasma-Lyte is a balanced, crystalloid intravenous fluid which has been shown to avoid the hyperchloremic metabolic acidosis associated with 0.9% sodium chloride. Data on physical, pH and chemical compatibility with other medicines are essential. Methods: The compatibility of adrenaline, dobutamine, dopamine, furosemide, midazolam, morphine and milrinone with Plasma-Lyte 148 (PLA) and Plasma-Lyte 148 with 5% glucose (PLA-G) was investigated. Control solutions were 0.9% sodium chloride and 5% glucose. Chemical stability was defined as < 5% concentration change with high-performance liquid chromatography (HPLC). Physical compatibility was assessed by checking for colour changes and precipitate formation. The pH of the admixtures was considered acceptable if between 5 and 9 at all time points. Six repeats were carried out for HPLC, 2 for physical compatibility checks and pH measurements, with all admixtures being tested at 0, 2 and 24 h after mixing. Results: All combinations were found to be chemically stable at 0, 2 and 24 h apart from furosemide with PLA-G at 24 h and midazolam with PLA or PLA-G at both 2 and 24 h. Only midazolam was physically incompatible when mixed with both Plasma-Lyte solutions. The pH remained stable in all admixtures, although not all pH values recorded were within the range of 5-9. Conclusion: All drugs excluding furosemide and midazolam were shown to be chemically, physically and pH stable at the tested concentrations when diluted with PLA and PLA-G.