The recurring transboundary Southeast Asian ‘haze’ is a prominent example of an international environmental crisis. Its negative social impacts encompass tourism, transport, agriculture, human health and life satisfaction, within Indonesia, Malaysia and Singapore. These countries are linked by culture and history, but cross-border relations have been damaged by ongoing political disagreements over haze. With a political solution to the crisis remaining elusive our project aims to uncover values held by people in the three countries which can be used to promote mutual understanding and cooperation related to haze. Our methodology combines insights from social psychology and international relations, and consists of two complementary studies, each covering all three of the haze-affected countries. Study 1 is quantitative, and employs a cross-sectional survey to examine haze-related knowledge, attitudes and behaviors and their links to wellbeing, environmental values and perceptions of neighboring countries. Study 2 is qualitative, and through focus groups will explore novel, haze-related values that can be contextualized within current patterns of cross-border sentiments and engagement. We anticipate our results will reveal public values as a pathway towards more constructive cross-border sentiments and engagement, and will have a wider significance given the current growth of cross-border environmental problems and values-driven politics.