The paper deals with the trend for Penman-Monteith reference evapotranspiration and climatic water deficit during the first decade of the 21st century in Southern Romania vs the 20th century. For the first half of the year the monthly evapotranspiration values were higher for the first decade of the 21st century vs the means of the 20th century. However, the trend reverses for the second half of the year, but for the whole year the totals were higher for the first decade of the 21st century vs the totals of the 20th century. The yearly temperature means in the first decade of the XXI century showed an increase in the three locations studied, respectively, vs century XX. This warming is responsible to a great extent for the increase in evapotranspiration, and the relationship between evapotranspiration and temperature was highly significant. Water deficit decreased in Constanta and Pitesti, but there was a slight increase in water deficit in the same period in Bucharest-Baneasa. Water deficit increased in the first half of the year and decreased in the second half during the first decade of century  XXI in all the three locations investigated vs century XX.