Because maize is so sensitive to weeds, weed control is an important factor in maintaining yields. The scarcity of manpower means that chemical weed control is the most commonly used method. The aim of the study was to assess the effectiveness of a post-emergence herbicide on weeds in maize crops. A completely randomised Fischer block design with nested control was used. The design consisted of seven treatments repeated four times. The floristic list, based on the «tour de champ» method, showed that broadleaf weeds predominated (78.36%). According to the European Weed Research Society rating scale, the herbicide based on Amicarbazone 74.667 g/l, Mesotrione 77.333 g/l and Nicosulfuron 40 g/l at doses of 0.75 l/ha and 1 l/ha was the most effective, with no signs of phytotoxicity. Yields were 8580 kg/ha at 0.75 l/ha and 9240 kg/ha at 1 l/ha of the product tested, compared with the reference controls 2,4-D amine salts (1 l/ha) and Nicosulfuron 40 g/l (1 l/ha) respectively, 5940 kg/ha and 5214 kg/ha, and the weed control (4620 kg/ha). Consequently, 0.75 l/ha of the product tested is recommended for post-emergence application to maize.