This paper deals with the study of the effects of (2-chloroethyl) phosphonic acid on leaf maturity of tobacco plants, Nicotiana tabacum L. cultivar "Goianinho". The experiment was set in the field and the product was used in order to uniformize and antecipate the leaf harvesting. The commercial product Ethrel (240 g/l of a.i.) was sprayed in the dosage of 2, 4,6, and 8 liters/ha at the stage of maximum growth of the leaves. Six days after this treatment the leaves were harvested, counted and weighted. The results have indicated that the vegetal regulator has promoted a more precocious ripening, thus antecipating and uniformizing the harvesting of the tobacco leaves, regardless the concentrations used in the experiment.