BACKGROUND This is a descriptive study of questionnaire responses of 682 members of three state ENAs, with supporting interview data from 26 of those participants. The objective was to determine (1) the types of clinical events perceived as critical and (2) the usefulness of critical incident stress debriefings for emergency nurses. METHODS Questionnaires asking emergency nurses to rate clinical incidents as critical and to respond to questions about their experiences with debriefings were sent to members of three state ENAs. Structured interviews about personal experiences with critical incidents and debriefings were conducted with 26 respondents. RESULTS Emergency nurses responding to the questionnaire viewed the death of a child and the death of a coworker as the most critical of the possible events. The majority of interviewees saw an incident related to the death of a child as the most critical in their careers. Of the questionnaire respondents, 32% had participated in debriefings; 88% of those found them helpful in reducing critical incident stress. CONCLUSIONS The findings suggest that managers should be alerted to the possibility of acute stress responses when emergency nurses experience a child's death. Education regarding stress and debriefings may be helpful to ED personnel.