Weed control with herbicides is a regular measure of the production technology of maize. In recent years the application of herbicides after emergence of maize and weeds (post-emergence) is getting more and more important. Herbicides which are applied after emergence of maize and weeds are often applied in tank mix with adjuvants, agents which enhance the effect of herbicides on weeds. Adjuvants are added to herbicides to broaden the spectrum of activity of herbicides or to reduce the dose rate of herbicides and keep the same effect on weeds. The experiments which were set in the field and controlled conditions investigated the effect of the herbicide topramezone at recommended and reduced rates and in combination with adjuvants COC, MSO, NIS, UAN, AMS, COC + UAN, AMS + COC, MSO + UAN, MSO + AMS, NIS + UAN and NIS + AMS. In field conditions, significantly better reduction of the number and fresh weight of the weeds was determined when reduced dose rates (66% recommended) of topramezone in combination with adjuvants COC + UAN, AMS + COC, MSO + UAN, MSO + AMS, NIS + NIS + UAN and AMS were used in comparison to the full dose rate without adjuvant. Study of the sensitivity of weed species Abutilon theophrasti Med., Ambrosia artemisiifolia L. and Amaranthus retroflexus L. to topramezone doses in combination with various adjuvants was determined by the sensitivity of these species. Ambrosia artemisiifolia is very sensitive to herbicide topramezone even without addition of adjuvants and dose required to reduce 90% of aboveground fresh weight (GR90) was 2.79 g a.i. ha-1 of topramezone. Abutilon theophrasti and Amaranthus retroflexus were moderately sensitive to topramezone. When adjuvant was added to tank mix, the value of GR90 for Abutilon theophrasti was significantly reduced. The GR90 value was more than double reduced when topramezone was in combination with the COC to up to fifteen-fold lower in the combination of MSO+AMS. Adjuvants have reduced the value of GR90 of herbicide topramezone on aboveground fresh weight on Amaranthus retroflexus from 18,5 to 490-fold.