Liquid ophthalmic products in opened multidose containers were studied to determine whether the date of opening was marked on the container and whether the drugs were contaminated. Pharmacy personnel collected opened containers for four months from a hospital's eye center clinic and outpatient surgery area. Half of the containers were randomly selected and the contents tested for bacterial and fungal contamination. The ophthalmic products were dripped from the containers' dropper tips into nutrient broth. Broth samples that became turbid after incubation were to be tested in the microbiology laboratory. Of 166 opened containers collected, 118 were marked with dates. The dates indicated that 97 had been opened within 30 days before collection; nursing policy dictated that containers be discarded 30 days after being opened. Acquisition cost for the undated, opened containers, which should have been discarded by nurses, was $182. In incubated samples from 81 opened containers, 61 of them dated and 52 dated within the past 30 days, no turbidity was seen. Although no bacterial or fungal contamination was detected in these ophthalmic products from opened containers, the absence of dates on some containers indicated deviation from institutional policy and probable avoidable waste of undated products.