A transient analysis of a double basin solar still has been presented. Explicit expressions have been derived for the temperatures of various components of the inverted absorber double basin solar still and it＇s efficiency. The effect of water depth in the lower basin on the performance of the system has been investigated comprehensively. For enunciation of the analytical results, numerical calculations have been made using meteorological parameters for a typical winter day in Delhi. It has been observed that the daily yield of an inverted absorber double basin solar still increases with the increase of water depth in the lower basin for a given water mass in the upper basin.