This research deals with the effects of application of three plant stimulants (Ergostim, Agrostemmin and Triacontanol) on growth of two sunflower cultivars (Uruguay and Anhandy), under greenhouse conditions. Sunflower was sowing in pots and Triacontanol (0.05 mg/l), Agrostemmin (l g/10 1/3 l) and Ergostim (1.5 ml/l) where applied 24 and 43 days after sowing. Ergostim and Agrostemmin promoted growth and increased dry matter production by sunflower plants. Triacontanol promoted flowering and reduced dry matter production.