Portuguese vitiviniculture represents an extremely important economic activity for the agricultural sector, particularly for some renowned winemaking regions, such as Alentejo, Dão, Douro, and Minho. Viticultural zoning allows tying the suitability of a given grapevine variety to the local soil and climatic conditions. Given the existing climate variability in the Portuguese territory and its likely changes in the future, this zoning is thus of utmost interest. In this study, the current viticultural zoning in Portugal is discussed, as well as changes induced by climate change in the period 2011-2070. For this purpose, daily temperatures and precipitation rates were used to calculate the Huglin, cool night, dryness and hydrothermal indices. A composite index based on the previous indices was also calculated. For the assessment of the recent past conditions (1961-2000), an observational dataset (E-OBS) was used, while for future climate projections, a dataset comprising 16 simulations of regional climate models (produced by the ENSEMBLES project) was considered. In the future climate, statistically signifi cant increases in the thermal indices are projected to occur in the next decades, while for the precipitation-based indices decreases might be expected, particularly over the south and innermost regions of Portugal. A reshaping of the main Portuguese winemaking regions is likely to occur in the upcoming decades, therefore emphasizing the need for the development of appropriate measures for the adaptation to or mitigation of these climatic changes at the level of varieties and rootstocks used, as well as at the implemented cultural practices, keeping the typicity and wine styles.