Emotions play a role in drawing people into activism and are a key dimension of activist experiences. However, although researchers have examined the political significance and ethical imperative of centring the voices and leadership of migrants in migrant rights struggles, there is limited consideration of how emotions are engaged in ways that inform, facilitate and challenge migrants in sustaining their activism. Through the case of undocumented youth activism in California, I explore how undocumented young people drew on practices of emotional reflexivity to navigate the complicated emotional register produced through activism as they reflected on their participation and trajectory through the undocumented youth movement. I suggest that the cultivation of storytelling spaces, cultures and practices within undocumented youth spaces supported and enhanced young people’s opportunities and capacity for engaging in relational practices of emotional reflexivity. These relational practices of emotional reflexivity supported young people to carve out expansive, dynamic and creative modes of activism that adapted to their shifting needs, circumstances and politics, while helping them to configure practices of care within the movement.