Concentrations of F(-), S and chlorophyll in needles of pines growing near metallurgical works and power plants were determined. A statistically significant positive correlation between F(-) (in the range of 4.32 to 21.98 microg F(-)/g d.m.) and chlorophyll and a negative correlation between S (in the range of 1094 to 2150 microg S/g d.m.) and chlorophyll was found. This result suggests an antagonistic interaction between F(-) and S in pine needles.