Montane forests are exposed to high ambient ozone (O<sub>3</sub>) concentrations that may adversely affect physiological processes in internal cells when O<sub>3</sub> molecules enter the plants through the stomata. This study addresses the model results of Phytotoxic Ozone Dose metric (POD) based on estimation of stomatal O<sub>3</sub> flux to dwarf mountain pine (<i>Pinus mugo</i>) and Swiss stone pine (<i>Pinus cembra</i>). We focused on two different bioclimatic regions: (1) the temperate mountain forests in the High Tatra Mts (SK–HT) of the Western Carpathians, and (2) the Mediterranean forests of the Alpes–Mercantour (FR–Alp) in the Alpes–Maritimes. Field measurement of O<sub>3</sub> concentration and meteorological data incorporated into deposition model DO<sub>3</sub>SE showed lower O<sub>3</sub> flux in FR–Alp than in SK–HT plots for the 2016 growing season. Model outputs showed that soil humidity play a key role in stomatal O<sub>3</sub> uptake by montane pines at the alpine timberline. We found that temperate climatic conditions in SK–HT with sufficient precipitation did not limit stomatal conductivity and O<sub>3</sub> uptake of <i>P. mugo</i> and <i>P. cembra</i>. On the other hand, the Mediterranean mountain climate characterised by warm and dry summer reduced stomatal conductance of pines in FR–Alp. POD without threshold limitation i.e. POD<sub>0</sub> as a recently developed biologically sounded O<sub>3</sub> metric varied near around and below critical level (CLef) depending upon different conditions of sunshine exposure in SK–HT plots. Field observation at these plots showed relatively weak visible O<sub>3</sub> injury on <i>P. cembra</i> (2 % and 7 %) when compared with <i>P. mugo</i> (8 % and 18 %) for one year (C+1) and two year (C+2) old needles, respectively. Despite of low POD0 values, clearly below CLef, the highest level of visible O<sub>3</sub> damage on average from 10 % (C+1) to 25 % (C+2) was observed on <i>P. cembra</i> needles in Mediterranean (FR–Alp) area. Further research is needed to clarify the effect of real soil moisture regime on stomatal closure in dry areas (FR–Alp) and resistance of pine species against visible O<sub>3</sub> injury in wet subalpine zones (SK–HT). More attention should be paid to O<sub>3</sub> fluxes covering a year-round growing season as well as intra-daily dynamics, especially the night hours, since these time spans appear to play significant role in O<sub>3</sub> uptake by mountain conifers.