Strawberry is a species sensitive to water shortages, especially during fruit growth and ripening. One method of limiting water loss in plant production involves the use of antitranspirants, which reduce plant transpiration. One method of limiting water loss in plant production involves the use of antitranspirants, which reduce plant transpiration. One of substances used for this purpose is, amongst others, natural terpene polymer - di-1-p-menthene (pinolene). Research on the influence of a pinolene-containing antitranspirant (with the commercial name of Vapor Gard) on gas exchange parameters (intensity of net CO₂ assimilation, intensity of transpiration, stomatal conductance for water, substomatal CO₂ concentration), the water balance and the content of assimilation pigments (chlorophyll “a”, “b”, total chlorophyll, carotenoids) in the leaves of the cv. ‘Salsa’ strawberry was conducted in the years 2009–2010. The antitranspirant was used once at a concentration of 0.75% before flowering. The measurements were performed four times: before flowering (1st measurement date), when the plants were in full flowering (2nd measurement date), in the middle of the harvest season (3rd measurement date) and after the end of the harvest season (4th measurement date). Foliar application of the Vapor Gard antitranspirant decreases the intensity of strawberry transpiration without changing the CO₂ assimilation activity. Plants sprayed with the tested preparation were characterised by a higher relative water content (RWC) in leaves and a higher value of the photosynthetic index of water use efficiency (WUE). The antitranspirant did not influence the content of assimilation pigments in strawberry leaves. The values of the determined physiological features depended on the measurement date (developmental stage) of the tested strawberry cultivar.