The anion-exchange enrichment of TlCl−4 coupled to flame AAS is applied to the determination of the total, pseudo-total (not bound in the silicate matrix) and mobile (plant available) content of thallium in soils. Ascorbic acid is used as a new efficient eluent of thallium. The limit of detection of the method is 0.04,μg/g, the relative standard deviation at the 1 μg/g level is about 3%. The method is rapid and simple.