To check the possible presence of a subglacial lake in Isunnguata Sermia, West Greenland we collected two 5 km perpendicular profiles of seismic reflection data. The data revealed a 1.9 km by 450 m and 50 m thick lens-shaped body at the bottom of a subglacial 190 m deep trough, most likely consisting of stratified consolidated sediments possibly overlain by dilatant till. Liquid water seems present at the northern and eastern flank of the subglacial trough. The bed on the northern side of the trough consists of unconsolidated, possibly water containing sediments, whereas on the southern side it consists of more consolidated material.