National conference didactic lectures have traditionally featured hour-long lecture-based presentations. However, there is evidence that longer lectures can lead to both decreased attention and retention of information. The authors sought to identify trends in lecture duration, lecture types, and number of speakers at four national emergency medicine (EM) conferences over a 6-year period. The authors performed a retrospective analysis of the length, number of speakers, and format of didactic lectures at four different national EM conferences over 6 years. The authors abstracted data from the national academic assemblies for the four largest not-for-profit EM organizations in the United States: American Academy of Emergency Medicine, American College of Emergency Physicians, Council of Emergency Medicine Residency Directors, and Society for Academic Emergency Medicine. There was a significant yearly decrease in the mean lecture lengths for three of the four conferences. There was an increase in the percentage of rapid fire sessions over the preceding 2 years with a corresponding decrease in the percentage of general educational sessions. There was no significant difference in the mean number of speakers per lecture. An analysis of 4210 didactic lecture sessions from the annual meetings of four national EM organizations over a 6-year period showed significant decreases in mean lecture length. These findings can help to guide EM continuing medical education conference planning and research.