Spring drought can adversely affect the pro-ductivity of barley (Hordeum vulgare L.) by reducing the yield. Because seed osmopriming can enhance crop pro-ductivity, we examined the potential of CaCl 2 treatment to improve drought tolerance in spring barley. Initially, we applied the priming procedure (5, 50, and 500 mM) to caryopses and assessed its effectiveness using a routine germination test, followed by measuring the level of divalent cations. Since drought adaptation is a complex phenomenon, we tested a comprehensive set of physio-logical parameters including (1) relative water content (RWC), (2) gas exchange parameters, and (3) photosyn-thetic pigments concentration in leaves of 3-week-old plants developed from the seeds subjected to osmopriming, followed by exposure to increasing water shortage. The plants were sampled at two selected time points, deter-mined by soil moisture retention (pF = 3.6 and 4.2). The effect of CaCl 2 pretreatment was characterized in three distinct spring barley varieties, which differed in their response to drought stress (drought-tolerant Sebastian and Cam/B1/C1 and drought-susceptible Georgie), to assess potential interactions between osmopriming and geneti-cally determined drought tolerance. Our results clearly demonstrate that CaCl 2 priming improves drought toler-ance in stress-tolerant as well as drought-susceptible barley cultivars. Furthermore, we show that the beneficial effects of calcium preconditioning interact significantly with genetically determined drought tolerance.