The article deals with the afforestation of agricultural land in the rural regions of Poland's eastern borderland. It presents changes in the area and dynamics of afforestation there and the spatial distribution of its intensity. Also identified are the determinants of farmland af-forestation. Special attention is paid to afforestation carried out on private land. The research covered three borderland provinces (Podlasie, Lublin and Subcarpathia) that form the east-ern boundary of the European Union. The years studied were 1996-2009, i.e. a period in which fundamental changes took place in farmland afforestation. The research showed that in the study area afforestation was largely carried out on private land, where it covered 26.7 thous. ha between 1996 and 2009. In each of the provinces under analysis the process of af-forestation of private farmland followed a similar pattern, but differed in dynamics. As in the entire country, in the rural eastern borderland one can observe an increase in the area of private land afforestation until 2003, its marked regression in 2004, another slight jump in 2005 and 2006, and another drop since 2007. The intensity of afforestation was not even; in the years under analysis it showed wide differences. Lower intensity of private farmland af-forestation was recorded in 1996-2001, at 3.4 ha per 1000 ha AL, than in 2002-2009, when the figure was 3.9 ha/1000 ha AL. But the intensity of farmland afforestation after 2001 kept declining with the changing peri-ods of afforestation co-funding.