The recent clinical demand for cefuroxime eye‐drops has given rise to practical difficulties because of the short shelf life recommended by the manufacturer of Zinacef injection, the product used to prepare the eye‐drops. The purpose of this investigation was to determine the stability of various formulations of cefuroxime sodium eye‐drops by high pressure liquid chromatography.The results showed that buffering the solution in the pH range 6.0 to 7.3 has little effect on the shelf life when compared with a simple aqueous solution of 5 per cent cefuroxime, which retains satisfactory potency for 21 days in a refrigerator at 2°C during simulated patient usage. Although stable for only 24 hours at room temperature, negligible loss of potency is observed after storing the eye‐drops for 12 months at ‐30°C. Frozen solutions should be defrosted at room temperature and shaken thoroughly to redisperse the cefuroxime evenly throughout the solution. Thawed solutions are stable in the refrigerator for a further 21 days at 2°C or for 14 days at 8°C.As temperatures up to 8°C are often recorded with domestic refrigerators, a 14 day shelf life is recommended in th