The cost of the energy extracted by ocean surface waves depends on many technological-physical factors like conversion principle, wave energy potential, water depth, shore distance, and ocean floor haracteristics. Economic factors, like assumed discount rate, cost reduction due to technological improvement and fiscal incentives, are extremely important too. The Tyrrhenian Sea, possesses an interesting energy potential. At some locations offshore Sardinia and Sicily the annual mean wave power per unit of wave front length is of the order of 10kW/m. In this paper the energy production has been computed for two different wave energy converters (AquaBuOY and Pelamis), at two promising locations in the western Italian seas. The energy cost has also been computed at Alghero and Mazara sites, which have the highest wave energy potential. The results indicate that the existing device converters are oversized with respect to the typical wavelength of the investigated sites. After proper scaling of the device, the performance in the energy conversion could become economically attractive also for Italian seas.