Abstract The present study was conducted to investigate the effects of gaseous hydrogen fluoride on tree leaves around an aluminium factory, which is a point source of pollution. The concentrations of the photosynthetic pigments, photosynthetic leaf areas, damaged leaf areas, energy contents and of the fluorides accumulated in leaves of Terminalia tomentosa and Buchanania lanzan, were measured, during June 1976 to February 1977. The photosynthetic leaf area, and the chlorophyll and energy contents increased from leaf bud stage to maturity and decreased thereafter. However, the concentration of fluoride increased steadily and was negatively correlated with the distance from the pollution source. Further, the content of fluoride were negatively correlated with that of chlorophyll, photosynthetic leaf areas and energy values. It is suggested that these reductions were a result of decreased photosynthetic efficiency, organic reserves and altered nutrient status of the plant; which ultimately resulted in metabolic perturbations.