Dandelion (Taraxacum officinale) was used in a KBN-supportcd project focused on the assessment of the extent to which Polish agricultural environment is contaminated with sulphur. Studies were carried out in different regions of the country. Sulphur content in leaves of that plant at full blooming varied with the level of sulphur contamination of soil and air. Dandelions from the heavily industrialised areas of the Upper Silesia, Legnica-Głogów Copper Mining District, and the Tarnobrzeg Sulphur Mining District showed high sulphur content and the S content (0.4%) in excess of the threshold value for this species.