Severe floods caused by glacier outburst have been frequent in the Nepal Himalayas, occurring more than every three years over the approximately thirty years since the 1960s. Nine potentially dangerous glaciers were identified from flight observations which were carried out in the Eastern and Central Nepal Himalayas on pre- and post-monsoon seasons in 1991. Field surveys were made at the beginning of April, 1992 to Imja Glacier lake located in Khumbu district of Eastern Nepal. This is one of the most dangerous typical glacier lakes that were identified by the flight observations. The field surveys revealed the maximum depth of the lake to be 98.5 m and the total amount of stored water to be 28 million m3. Since this lake is dammed up by ice-cored moraine it is concluded as one of the most dangerous glacier lakes in the Himalayas.