This study deals with the question of how winegrowing in Spain may be altered by anthropogenic climate change. The present state and expected future development of three bioclimatic indices relevant for winegrowing were assessed by observation, and four regional climate models from the EU-ENSEMBLES project were investigated. When comparing the 2061–2090 scenario period to the 1961–1990 reference period, the models unanimously indicate a significant increase in the mean of the two considered thermal indices over the entire study region. However, for the index based on temperature and precipitation, the models are heavily biased when verified against observations and generally disagree on the size of the projected future change. For this index, unanimous model agreement was only found for northwestern Spain where all models indicated a significant decrease in the mean. From these results, regional climate change is expected to negatively affect the quality of wine in the growing regions of central and southern Spain, and the Ebro valley, whereas positive effects should be expected in the northwest. No significant changes in the risk of mildew infestation are to be expected except for the northwest, where this risk is projected to decrease. ; This work was supported by the Xunta de Galicia under Research Grant No. 10PXIB383169PR and co-financing by European Regional Development Fund (FEDER). Alexandre M. Ramos was supported by the Portuguese Foundation for Science and Technology (FCT) through Grant FCT/DFRH/SFRH/BPD/84328/2012. S. Brands would like to thank the Consejo Superior de Investigaciones Científicas JAE-PREDOC programme for financial support. ; Peer Reviewed