Because of increasing concern about the appropriate and cost-effective use of eye care services and procedures, several organizations have sought to arrive at practice guidelines or practice patterns from which physicians can draw guidance. To assess the potential effectiveness of such guidelines, we reviewed the care of patients with corneal ulcers. Corneal specialists recommend that cultures be obtained before initiation of treatment. We determined whether ophthalmologists implemented these guidelines by the following: (1) a review of records of 79 patients referred to a tertiary care corneal and external disease service for evaluation of keratitis, and (2) a survey by mail of practicing ophthalmologists. Antibiotic therapy without any cultures was observed in 38 of 79 referred patients with corneal ulcers (48.1%). Our survey of general ophthalmologists disclosed that 274 of 560 patients with corneal ulcers (48.7%) were treated with antibiotics without any cultures being obtained. Compliance with recommended practice in the care of corneal ulcers is poor, as measured with either method. This procedure provides insights into more effective implementation of future practice guidelines.