Monitoring of forest condition in Turkey started in 2006 when a 16x16 km grid of Level I plots was established. In 2007, the first 48 Pinus brutia plots were surveyed for crown condition. In 2008 and 2009, the plots were 398 and 563, respectively. In 2007, the mean defoliation for P. brutia was 13.0 %. In 20082009, the mean defoliation was 19.5-19.8 % and 27.0-23.0 % for coniferous and broadleaved species, respectively. Defoliation was higher than 25 % on 24.6-18.7 % of the monitored trees. The species with the highest defoliation were Carpinus betulus and Juniperus foetidissima in 2008, and Quercus pubescens and Juniperus communis in 2009. The slight improvement in forest health in 2009 may be attributed to better weather conditions than in 2008 (higher precipitation). The forests along the Black Sea coast of Thrace showed the highest defoliation in both 2008 and 2009. This may be due to transboundary air pollution from Istanbul, where sources of sulphate and nitrate pollution occur. Elevated defoliation rates were also observed in the Black Sea region; they were most probably caused by biotic factors in plots subject to industrial pollution.