Investigations were made in Martonvásár on the herbicide tolerance of 22 inbred maize lines and 3 parental single crosses when treated with one herbicide applied after sowing, prior to emergence, and with seven applied post-emergence in the 6-8-leaf stage. Visible damage was scored 14 days after the treatment. An analysis of the phytotoxic effects led to the conclusion that a single dose of the tested herbicides did not cause any damage to the genotypes investigated, with the exception of one inbred line, which was extremely sensitive to herbicides of the sulphonyl carbamide type and moderately sensitive to both rates of dicamba. In many cases, a double dose of the herbicides caused mild or moderate symptoms on the maize lines.