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Drought is one of the important problems influencing forest ecosystems. This problem has been getting more attention recently due to impacts of global warming. Drought could decrease aboveground growth of plants by 30-70% and restrict their natural distribution boundary and biodiversity. Growth of trees is controlled by the availability of water up to 80-90%. In Turkey, drought triggered forest tree mortalities have been observed in leeward sides of Black Sea Region, Central Anatolian Region and Aegean Region. Dead trees of Scots pine and oriental spruce found in Black Sea Region, of black pine, scots pine and fir in Central Anatolian Region and of brutian pine in Aegean Region. In addition, drought triggered bark beetle infestation that caused dying of thousands of spruce trees in Eastern Black Sea Region. Main reasons of increasing drought effect are global warming, overgrazing, conversion of grassland and forest areas into croplands and increased erosion in Turkey. Grassland area in Turkey was 38.9 million ha in 1949 and this area had been decreased to 28.3 million ha till 1969 and today is 21.8 million ha. While agricultural land area was 8.5 million ha in 1935, it increased to 25 million ha in 1970 and today it is 28 million ha. Meanwhile forested land area had been decreased up to 2.6 million ha from 1950 to 1997. In Turkey, drought tolerant ecotypes of important timber species need to be selected in order to reduce the potential effects of global warming on tree mortalities. Additionally, drought risk maps of forest areas should be prepared to determine drought risk assessment and take necessary measures. Drought can further accelerate the effects and extent of erosion. Therefore, it is also important to account the effects of erosion on the productivity of agricultural and forest goods. Finally, effects of global warming need to be incorporated into afforestation strategies of Turkey.