Because the identification and reporting of medication administration errors (MAE) is a nonautomated and voluntary process, it is important to understand potential barriers to MAE reporting. This paper describes and analyzes a survey instrument designed to assist in evaluating the relative importance of 15 different potential MAE-reporting barriers. Based on the responses of over 1300 nurses and a confirmatory LISREL analysis, the 15 potential barriers are combined into 4 subscales: Disagreement Over Error, Reporting Effort, Fear, and Administrative Response. The psychometric properties of this instrument and descriptive profiles are presented. Specific suggestions for enhancing MAE reporting are discussed.