The massive Kosi River floods of August 2008 caused unprecedented loss to lives, livelihoods, infrastructure and property in north-eastern Bihar. Although floods have been a recurring feature in parts of the state, the 2008 floods were not usual. The Kosi burst its embankments and changed course, inundating areas of Bihar that had not experienced such flooding for half a century. About 1,000 villages in five districts (Araria, Madhepura, Purnia, Saharsa and Supaul) were affected, involving three million people, of whom about one million were evacuated. This perception survey was conducted to document the experiences of affected groups; explore the extent of damage at village and household levels; document impacts on shelter, access to food, water and sanitation, health and education, and livelihoods; identify coping mechanisms of people belonging to different social and occupational groups; and document potential recovery mechanisms as suggested by people. A total of 40 broadly representative villages were surveyed, as well as 820 sample households, of which 377 respondents were women; another 200 respondents from relief camps were selected. Focus Group Discussions (FGDs) were held with people belonging to various social groups in 20 out of 40 villages, where household surveys were not conducted.