Thirty-eight 911 systems across the United States were randomly selected and studied to determine those elements and procedures related to effective 911 public education programs. The public education effectiveness criterion was a high degree of public understanding of the proper use of the 911 emergency telephone lines, which was measured by the ratio of appropriate calls to inappropriate calls. Jurisdictions that used public education both before and after the 911 system cutover were more likely to be highly effective than jurisdictions that used public education only after system cutover. Further, systems that used several different education activities were more likely to be highly effective than systems which used few activities; however, a few activities spread out before and after cutover were more likely to be effective than many activities performed only after cutover. Billboards, telephone stickers, utility bill fliers, and talks to community organizations and schools were more frequently associated with highly effective 911 systems than would be expected in a neutral distribution. Newspaper articles and radio messages were so commonly used that their association with effectiveness could not be determined. Preliminary activities for a 911 public education program should include (1) assigning responsibility, (2) clarifying agency procedures, (3) inventorying available media, (4) identifying special public groups, (5) developing a public education program schedule, and (6) developing presentations for selected media. Appended are a discussion of the study methodology and sample 911 public education materials.