Solar direct steam generation is considered as a promising technology for steam production in thermalpower generation due to high temperature levels that can be achieved compared to other technologiesthat use indirect steam generation. This paper demonstrates exergy and exergoeconomic analysis ofcommercial-size direct steam generation parabolic trough solar thermal power plant. For steam powercycles, reheating might be necessary to avoid great wetness of steam which shortens the lifetime ofthe turbines. Therefore, two configurations have been considered in this study; the non-reheating config-uration as well as reheating by steam–steam heat exchanger. For each component, exergy andexergy-costing balance equations have been formulated based on a proper definition of fuel–product–loss. Exergy results show that particular attention should be paid to solar field, condenser, low pressureturbine and high pressure turbine (in a descendant order) as they constitute the major sources of exergydestruction. Results from exergoeconomic analysis, however, show that the condenser should be thefourth component in the order of importance after the solar field and low/high pressure turbines.Increasing the temperature at the inlet of the low pressure turbine by 100 K using steam–steam reheatingis shown to result in 9.1% increase in the vapor fraction at the exit of turbine. This increase in steam qual-ity, however, would be achieved by drop less than 1.5% in thermal and exergetic efficiencies, and about2% increase in cost of electricity. Moreover, the effect of degree of reheating on exergetic exergoeconomicparameters has been investigated. The results revealed that there is a specific value of degree of reheatingfor which the exergetic efficiency would be on it’s lowest value. This point would be of importance duringoptimization procedure of reheating direct steam generation solar plants