To date, the nature and role of ATC personnel in aviation accidents and incidents has yet to be fully examined. To remedy this situation, a comprehensive review of ATC-related accidents and incidents that occurred between January 1985 and December 1997 was conducted using records maintained by the NTSB. Results of the analysis revealed that ATC-related accidents and incidents are infrequent events. However, when these events do occur they are likely to involve local controllers interacting with multiple aircraft in the air during daylight VFR conditions. An in depth analysis of the narrative reports using the Human Factors Analysis and Classification System (HFACS) revealed that skill-based errors (attention failures and memory lapses) were the most common type of error committed by ATC personnel. Supervisory and organizational factors such as controller training, procedures, and oversight were cited in only a small fraction of the incident and accident reports. However, current accident and incident reporting systems were not designed with ATC errors in mind, making the analysis of latent factors, such as supervisory and organizational issues, extremely difficult. What is needed is a new error-analysis framework that will facilitate the gathering of information during ATC-related accident and incident investigations.