It was studied the influence of 2-choroethyl phosphonic acid (Ethrel) on flowering induction of indeterminate tomato, cv. "Santa Cruz Gigante", applied in different stages of development (one, four and eight weeks after transplanting) in 100, 200, 300 and 400 ppm concentrations of the product. It was observed that higher concentrations (300 and 400 ppm) provocated withing of plants and posterior abscision of part of inflorescence without reduction of the yield when applied during flowering. It was not observed neither flower induction nor increasing in productivity.