The aim of this study was to estimate the water needs of grapevines (Vitis vinifera L.) in the different regions of Poland. The grapevines water requirements, considered as the crop evapotranspiration, were determined using the plant coefficient method. The grapevine plants crop evapotranspiration was measured using the reference evapotranspiration and plant coefficients. The plant coefficients were adapted to the reference evapotranspiration that was calculated using the Blaney Criddle’s formula, modified for Polish conditions by Żakowicz. The grapevines water needs were determined for five agro climatic regions of Poland with the representative meteorological stations. The calculations of grapevines water requirements have been carried out for the thirty year period determined from 1981 to 2010. The study based on the six month growing season established from May 1 to October 31. As the irrigation period, four months, including May, June, July and August, were considered. The highest grapevines water needs (440 mm), during the growing season, in the north west and central east region of Poland were observed. While the lowest water requirements in the south east (414 mm) and north east (415 mm) region of the country were revealed. During the irrigation period, the highest grapevines water needs occurred in the central north west (355 mm) and central east (353 mm) region of Poland, while the lowest (329 mm) – in the south east region of the country. The upward time trend of the grapevines water requirements was observed both in the growing season and in the irrigation period. With the exception of the central north west region, this time trend was significant throughout Poland. The highest increase of grapevines water needs in the growing season (by 6.9 mm in each subsequent ten year period) in the central east and south east region of Poland was revealed. In the irrigation period, the highest rise of grapevines water requirements in the south west (7.4 mm decade-1) and south east (7.6 mm decade-1) region of the country was noted. The highest rainfall deficit was observed in the central north west region of Poland; 125 mm during the growing season, and 117 mm in the irrigation period.