This study investigated the experiences of people with developmental disabilities in self-advocacy groups to better understand the self-advocacy movement, which is currently in its developing stage in Korea. Face-to-face interviews with 18 people with disabilities were conducted. Study participants got involved in self-advocacy groups with the expectation of 'voicing our stories', 'meeting new peers', and 'expanding the scope of activity in their local communities'. They participated in various activities from leisure to group advocacy against discrimination based on disability. After participating in self-advocacy groups, they expressed self-confidence, improved their communication skills, and developed new goals for their own lives. Participation in self-advocacy groups helped them replace feelings of loneliness with belonging and expanded their involvement in independent activities and leadership roles. Points of interests This article examines the experiences of people with developmental disabilities in self-advocacy groups in Korea. People joined self-advocacy groups to tell their stories, meet new people, and participate in more activities in the community. People developed communication, leadership, and self-determination skills and reported less loneliness, more confidence, and a greater sense of belonging. People wanted to increase their self-advocacy group's activities and membership, have leadership roles, and further advocate for non-discrimination and equal rights for people with developmental disabilities. Funding and supporters outside of service providers is suggested to give people with developmental disabilities equal power to lead the self-advocacy movement.