Errors resulting in adverse events in the medical care system are ubiquitous and underreported. Critical incident techniques that have been used to reduce errors in aviation have recently been applied to evaluate adverse events in the critical care arena. We report an evaluation of interrater agreement on responses to questions concerning adverse event reporting using a computer-based medical incident reporting system (MIRS). Thirty-four intensive care unit staff volunteers reviewed five fabricated test cases containing iatrogenic factors, then completed an incident report for each case using the MIRS. Interrater agreement was significant for all five cases (p < 0.01). The time required to complete a report decreased significantly from the first case to the last (p < 0.01). Overall, the MIRS was perceived as a relatively quick (< 6 minutes) and comprehensive reporting tool. The results indicate that health care providers report adverse events similarly, suggesting that the MIRS would be a useful tool in the reduction of errors (as a process improvement program) and to facilitate the continuing process of health care improvement.