Undergraduate nursing students are expected to be responsive and competency, particularly during a disaster. Working as health volunteers is one strategy to develop these skills. However, little research has investigated the experiences of nursing students working as health volunteers during a disaster. This study aimed to investigate undergraduate nursing student perceptions and experiences of being health volunteer during the Mt. Merapi eruption. Methods: A non-experimental, descriptive design was used. A sampling of 25 undergraduate nurse students who worked as health volunteers during the Mt. Merapi eruption completed a self-administered questionnaire. The questionnaire consisted open- and closed-ended questions, and was used to measure students' self awareness and what they have learned. Additional questions were asked to prioritize attributes required to be health volunteers. Data were aggregated and analyzed using a simple, descriptive analysis. Undergraduate nursing students had internal motivation of being health volunteers during disaster. Findings of this study illustrated benefits, future impact of being health volunteer, and required attributes of being good health volunteers. Students' perceptions and experiences during disasters underscores important factors in the promotion of disaster management competency in nursing education.