It is known that the Kingdom of Bhutan is subject to dangerous glacial lake outburst floods (GLOFs). Gansser (1966, 1970), for example, described the GLOFs in northern Bhutan, and proposed to take measures to minimize the risks (Gansser, 1970, 1978). However, unfortunately, little effort has been made and a catastrophic outburst of two glacial lakes in the Lunana area, northern Bhutan on 6 October 1994 resulted in the deaths of 21 persons. In spite of the damage, including the loss of lives, the details of the 1994 incident in Bhutan are not available, partly because of the political background and partly because of the geographical situation. The second author, who lived in Bhutan from 1990 until 1994, obtained a video tape showing the flooding and observed the area along the lower Pho Chhu after the incident, and the first author collected information about the incident through several sources. The authors, therefore, have not conducted scientific research, and their information concerning the flood is rather limited. Nevertheless, it is hoped that this report of the damage caused by the 1994 outburst flood in northern Bhutan and the review of the