Response of radial growth of Pinus sylvestris to pollution caused by oil shale fly ash deposition on forest stands in the vicinity of the Baltic Power Plant, North-East Estonia, was studied. Multivariate analysis indicated that oil shale fly ash may promote annual radial growth of Scots pine. The coefficients for emission predictors were positive in all computed regression equations. The favourable impact of oil shale fly ash on the radial growth of younger trees started to decrease after 3-4 years. In the case of older trees the impact of oil shale fly ash emissions lasted 5-6 years.