Increasing urban surface temperature due to change of natural surfaces is one of the growing environmental problems in urban areas, especially in cities like Delhi. The present work is an attempt to assess the urban surface temperature in Delhi using remote sensing and GIS techniques. ASTER datasets of thermal bands were used to assess the land surface temperature (LST) using temperature emissivity separation technique. Ward-wise population density was calculated from the Census of India 2001 data to correlate the population density with LST.