In order to monitor the changes in the glaciers in the Bhutan Himalaya, a repeat decadal glacier inventory was carried out from Landsat images of 1980, 1990, 2000 and 2010. The base map of glacier polygons was obtained from the object-based image classification (OBIC) method using the multispectral Landsat images of 2010. This method is used separately to delineate clean-ice and debris-covered glaciers. Later these two layers were merged to a single layer to obtain the glacier parameters of 2010. The glacier polygons of 2010 are modified manually by overlaying separately the Landsat images of 2000, 1990 and 1980 to obtain the glacier polygons of the respective years. The inventory of 2010 shows 885 glaciers with total area of about 642 km2. The glacier area is 1.6% of total land cover in Bhutan. The result of repeat inventory shows 23.4 ± 0.9% glacial area loss between 1980 and 2010, with the highest loss of 11.6 ± 1.2% between 1980 and 1990 and the lowest of 6.7 ± 0.1% between 2000 and 2010. The trend of glacier area changes from the 1980s to 2010 is found as –6.4 ± 1.6%. Loss of glacier area was mostly observed below an elevation of 5600 m a.s.l. and was greater for clean-ice glaciers. The upward shifting of equilibrium-line altitudes (ELA) has been noticed from 5170 ± 110 m a.s.l. to 5350 ± 150 m a.s.l. in the years 1980–2010.