To assess nurses' knowledge of botulism, a Centers for Disease Control Category A bioterrorism agent, one case of which constitutes an emergency. The study utilized survey research. The cluster sample included 1,414 registered nurses. The survey gathered demographic data and nurses' knowledge of the background, manifestation and management of botulism. The mean percentage of correct answers for the sample was 25.95%, with a standard deviation (SD) of ±19.89%. Only 90 (6.3%) achieved 60% or more correct. Educational preparation, experience, specialty/area of practice and whether nurses had a class in disaster medicine were also examined and although differences were noted, none of these factors accounted for a score of 60% or above. The results of this study indicate the need for an assessment of the current education nurses receive about botulism.