River bank erosion is a recurrent problem in Bangladesh. It has a devastating impact on the socio- economic condition of the study area. The main purpose of the research work was to depict the socio- economic impact of river bank erosion in Sadar upazilla of Gaibandha District in Bangladesh since 1988 to 2008 caused by the Bramhaputra river. Data were collected by interviewing 100 randomly selected families among the 514 displaced families in the study area during the period of August 2009 to October 2009. Secondary data were also collected to explain the erosion status. Bangladesh is having a complex of intricate river and channels most of which are shifting in nature and thus river bank erosion is common. River migration and thereby the land degradation due to river erosion and flood displace about one million population annually. In this context that the present study intends to investigate into the relationship between river erosion and its impact on the socio-economic condition of the displaced population.