This article is focused on the evaluation of the Al/Ca ratio in fine roots of Norway spruce on the plots belonging to the ICP Forests monitoring programme in the Czech Republic. In total 122 fine root samples were collected from twenty plots from two soil layers of 0-10 and 10-20 cm and then analysed. The mean Ca/Al molar ratio in the fine roots from the 0-10 cm topsoil layer is higher than in the lower 10-20 cm soil layer, which corresponds to the distribution of fine roots -on average 80% of fine roots were found in the topsoil. 6% of the samples in the lower soil layer strongly indicate aluminium stress (Ca/Al < 0.1) and 30% of the samples may demonstrate the adverse effects of aluminium (< 0.2). On the other hand, no relationship was found between the Ca/Al ratio in the fine roots and the fine root biomass and vitality or crown condition. These results suggest that the potential aluminium toxicity is not the driving factor of the crown condition in Norway spruce and the Ca/Al ratio itself does not pose a risk to forest health in the region.