Objective: To determine the effect of a practice guideline on the process of ED care in a health maintenance organization. Methods: A pre—post-intervention comparison with a one-year pre-intervention phase followed by a one-year post-educational intervention phase was used to study the effect of the guideline on ED care. Emergency physicians and nurses were provided the details of the guideline during a two-week interval between the two periods. Results: During the two years of the study, 1,140 preintervention and 759 post-intervention patients met study eligibility criteria. More patients were diagnosed as having had falls due to loss of consciousness, stroke, and seizures during the post-intervention period (pre-intervention 3.8% vs post-intervention 8.4%, p < 0.001). There was a significant improvement in documentation of six of ten history items: cause of fall (64.5% vs 72.9%), location of fall (54.7% vs 60.5%), ability to get up unassisted (5.4% vs 12.5%), long lie after fall (1.5% vs 10.1%), prescription medications (79.0% vs 92.2%), and Pneumovax immunization status (20.8% vs 43.0%); and two of the four physical examination items: visual acuity (1.5% vs 3.2%) and the “get up and go test” (1.3% vs 11.2%). Prescribing of calcium and vitamin D increased from 0% to 6.6%. Conclusions: The educational intervention to the practice guideline for the ED management of falls in elders led to small but significant improvements in the documentation of selected history and physical examination items and the prescribing of calcium and vitamin D, and to a greater consideration of the causes of falls.