Libya is a very and country with poor water resources that relies mostly on rainfall and underground water. It has been suffering from water shortage problems for the last three decades due to lack of rainfall, which has led to the over-exploitation of ground water, and an increase in population. The water deficit is expected to reach about 4700 Mm(3)/y. Since 85% of the population is concentrated along the coastal area, desalting of seawater is essential to meet the demand for potable water. Desalination is an energy-intensive process, thereby the required energy to desalt such large amounts of seawater is very considerable. Selecting the proper energy source will have a positive effect on the product water cost. A comparison of different energy sources coupled to commercially available desalination technologies was performed to assess economic competitiveness of nuclear desalination in Libya for two selected sites: the Tripoli site (Site 1) and the Sirt site (Site 11), with a production capacity of 250,000 m(3)/d and 40,000 m(3)/d, respectively. The results of comparing the product water cost for the three major desalination processes MSF, MED and RO, show ranges of values from a minimum of 0.87$/m(3) for the MED process coupled with a steam boiler at site 1, to a maximum of 1.78$/m(3) for the MSF process coupled with a SMART-type nuclear reactor at Site II.