Environmental and social assessments (EIA and SIA) are crucial tools for making environmental decisions about projects and plans. The research carried out in the JUSTNORTH case studies shows that these assessments affect justice in the Arctic—they can help or hinder it. People involved in consultations often feel that the EIA processes happen too late, especially in the European Arctic, and don't properly consider social impacts. Public participation is a major challenge due to limited capacities, power differences, and dissatisfaction with its effectiveness. Combining scientific and traditional knowledge in these assessments is tough. The impact of past injustices and the balance between global climate benefits and local harm aren't well-addressed either. Regulations for these assessments are better developed in some parts of the Arctic than others, and involvement of young people and vulnerable groups in consultations is limited.