The purpose of this study is to investigate the experiences and perceptions of educational volunteer among pre-service science teachers. To explore these aspects, a survey was administered to 72 pre-service science teachers enrolled in a teacher education program. The survey examined participation patterns, perceived teaching competencies, and relevance to their major. The findings of this study are as follows: First, pre-service science teachers primarily engaged in volunteer activities during their early undergraduate years, often selecting institutions based on location and available time rather than on major relevance. Second, those who participated in major-related educational volunteer perceived them as more appropriate and meaningful. Third, participants reported improvements in communication, collaboration, student interaction, and prosocial behavior, although their skills in lesson design and planning showed only modest growth. Lastly, educational volunteer also contributed to clarifying their teaching career aspirations. However, participants identified several challenges, such as unstructured program management and limited alignment with academic content. These findings suggest the need for systematically designed, major-related volunteer programs and institutional support to enhance the educational value of volunteer for future science teachers.