Nowadays due to significant increasing in power and water demand, most of the improvement challenging focuses on selecting the optimum cogeneration option and considering technical and economical aspects of the project. This paper provides Thermoeconomic analysis of Qeshm Power and Fresh Water Plant, including typically simple cycle power plant coupling with MED-TVC thermal desalination system. Mentioned plant based on GT-HRSG-MED produces 40 MW electricity and 2 MIGD desalinated water by MED-TVC units. Hence, the aim is to offer a proven alternative for new units for best utilization of GT exhaust gas potential, based on combined gas/steam turbine cycle, which make steam turbine electricity production as a byproduct of delivering steam to desalination process, while meeting the minimum desired market requirement and providing the best return on investment based on the proposed economic assumptions. A thermodynamic modeling based on the energy and exergy analysis is performed while The cost equations for the Purchased Equipment Costs (PEC), Fuel cost (F) and the Operating and Maintenance cost (OM) are derived in order to obtaining the water production cost, capital investment for proposed plant. The results show that an increase in pressure level by 219 % results in a decrease in power production by 7 % and in IRR by 4.5 %, but increase in water production (MIGD) by 20 %. Comparison between configurations indicates lowest pressure for the proposed plant will be as the optimal configuration scheme covers the minimum water generation demands by 3.31 MIGD water productions.