Abstract Combining insights from migration and climate adaptation studies, this study examines how migrants living in Belgium contribute to climate adaptation in their region of origin, based on 29 qualitative interviews with migrants in Belgium. The findings varied considerably, depending on the region of origin, the main driver of migration and the possibility of returning. The results show that both the knowledge and capacity to contribute to climate adaptation in the region of origin depends on the forms and degrees of capital individuals have, both in the immigrant country and region of origin. Migrants with more cultural capital in the region of origin had more transnational bonding and bridging ties, resulting in more opportunities to contribute to the development of the region. However, as many of the interviewees originated from urban areas, their actions were oriented more towards waste, pollution and life domains other than climate adaptation. This contrasts with migrants with less formal cultural capital. Due to specific living conditions, they were more familiar with local climate impacts. Their transnational bonding social ties increased this knowledge and familiarity with the need for climate adaptation. Nevertheless, the high costs of integration into the immigrant society and a lack of cultural and economic capital limits this group's capacity to contribute to climate adaptation initiatives in the region of origin. Bringing the concept of ‘migrant capital’ into the study of climate adaptation fills a gap in the literature on environmental migration, and especially engages with discourses that frame migration as an adaptation strategy.