Global crop production systems are challenged by the increasing areas of saline soil in arid and semi-arid regions. Two naked oat (Avena sativa L.) genotypes, ‘VAO-7' and ‘VAO-24', were subjected to different salt concentrations (0, 50, 100, 150, 200, and 250 mM NaCl) to determine the effects of salt levels and stress duration on seedling growth, ion content and photosynthetic productivity. Relative growth rate (RGR) and leaf chlorophyll were determined at weekly intervals after salinity was imposed. Total leaf area, plant dry weight, photosynthetic parameters, and plant tissue ion concentrations were determined at 25 d after salinity application. Under salt stress conditions, germination rates varied greatly among the genotypes. The differences between VAO-7 and VAO-24 for most parameters measured were significant after 2 wks of stress introduction at 200 and 250 mM NaCl.  Great differences were observed for total leaf area and plant dry matter. At 25 d after salt stress, plants treated with the 250 mM NaCl accumulated 36-fold more Na⁺, 78.6% more Ca²⁺ and 2.4-fold less K⁺ than the control. Salt treatment resulted in the reduction of almost all the growth parameters, companioned with increases in plant Na⁺ and Ca²⁺ concentrations. Spikelet and tiller number per plant were the most salt-sensitive factors of yield components. Our data indicate that there is great variability for salt tolerance among naked oat germplasms as well as highlights the parameters for potential selection.