The present study utilizes the waste heat streams, jacket water and exhaust gas from a Diesel engine as the heat source for desalination of seawater. The seawater is preheated to a saturated state, and then, throttling and heat exchange processes are alternately employed, for generation of fresh water. The exit brine is eventually crystallized to salt via the wind. In the evaluation, the temperature differences among the stages of the evaporator significantly influence the generation rate of fresh water. Accompanying the use of plastic heat exchangers, the brine related dirt problem could be avoided. The appropriate arrangement of the waste heat utilization could not only omit installation of the warm water discharge system but also prevent damage to the underwater ecology. The study successfully shows the feasibility of application of waste heat from combustion engines in the desalination of seawater.