The Kosi river fan located in the northern part of India is one of the largest alluvial cones built by any river in the world. This 180 km long and 1501cm wide alluvial cone shows evidence of lateral shift exceeding 140 km during the past 250 years. The Kosi alluvial cone and its adjoining area has been studied in detail by remote sensing techniques. The data have been integrated with the available geological and geophysical information to decipher the causes responsible for the lateral shift of such a high magnitude fan.