Mechanization of threshing and separation of Origanum onites is limited by practical constraints. In this study, we investigated the effects of moisture content on physical and mechanical properties of O. onites to be applied to the design of mechanized threshing and separation operations. Leaf, stalk and flower dimensions, projection area, picking force, leaf-to-stalk ratio, leaf-to-flower ratio, and essential oil content of O. onites were determined at three different moisture contents: 8.9 %, 11.4 %, and 15.0 % (d.b). Most parameters increased linearly with increasing moisture content. The essential oil content of O. onites decreased with increasing moisture content. Moisture content had a significant effect on the physical and mechanical properties of O. onites. Flower picking force of O. onites varied between 3.630 and 4.050 N and Leaf picking force of O. onites varied between 0.375 and 0.974 N. Data on stem diameter are used for designing threshing and separation machinery, while data on flower projection area are required for effective transport, cleaning, and separation of O. onites. Moisture content of O. onites should be optimized to achieve ideal machinery design, as well as energy, power, and cost savings.