The objectives of the present research were to determine the effect of a single application of herbicides used in maize on voluntary sunflower plants. The field experiments were con ducted in maize field with voluntary sunflower plants. Their density ranged from 5-30 plants/m2. In the early treatments up to four leaves stage of maize were applied: 2,4-D + Atrazin SC; 2,4-D estar + Starane 250; 2,4-D estar; Banvel 480; Banvel 480 + Deltazon; Banvel 480 + atrazin and in later treat ments up to six to eight leaves of maize: Motivel + Calisto; Cambio; Lumax; Calisto + Gesaprim; Calisto; Grid + Esteron; Tarot + Peak; Motivel + Cambio; Motivel + Peak; Motivel + Banvel; Equip + Esteron; Equip + Banvel; Equip + Peak; Grid; Grid + Esteron; Tarot + Cambio; Tarot + Calisto; Tarot plus + Murtonik; Lumax; Peak and Ring + Atrazin Sc. In early treatments voluntary sunflower plants were in cotylledon stage up to first leaves pair stage and used herbicides were 100% effective, but 15 days after treatments retrovegetation was expressive. In later treatments voluntary sunflower plants were in cotylledons up to three leaves pairs. Used herbicides were 100% effective only in a young plants (up to first leaves pair stage) older plants were injured but survived.