Disaster preparedness in schools is critical for the health and well-being of students and staff. To enhance disaster preparedness, awareness of disaster prevention should be raised among teachers. The aim of the current study was to assess disaster prevention awareness among teachers and to clarify the relationship between disaster prevention awareness and concern regarding disaster preparedness. Teachers from special needs schools, for which disaster preparedness is particularly important, were selected. Study questionnaires were sent to 1310 schools for children with special health care needs across 47 Japanese prefectures. Five-hundred-and-thirty-one complete responses were obtained. The disaster preparedness in the schools was insufficient. Teachers were concerned about child management, life saving, life maintenance, evacuation shelter management, and school management. There was a positive correlation between disaster prevention awareness and concern about disaster (r = 0.217, p-value = 0.000). The disaster awareness scale items “A sense of crisis about disaster” and “Anxiety” were positively correlated with concern about disaster, whereas “Imagining the disaster situation” was negatively correlated with concern about disaster. The current study analyzed the relationship between disaster prevention awareness and concern regarding disaster preparedness, which is relevant for the practice and indicates the importance of imagination strengthening.