The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is principally used in agriculture and may pose toxic risks to some crops. Thus, the goal of the present study was to evaluate the genotoxic properties of 2,4-D by using randomly amplified polymorphic DNA (RAPD) assay in the root of maize (Zea mays L) seedlings. For this purpose maize seedlings were treated with aqueous solutions of 2,4-D at concentrations ranging from 0.5 ppm to 2 ppm for 7 days. After the growth, root length, total soluble protein levels and RAPD profiles of the seedlings were analyzed to determine genotoxicity. The results showed that increasing concentrations of 2,4-D caused a decrease in the root length and an increase in the total soluble protein levels of the seedlings. The changes occurred in the RAPD profiles of the root tips following 2,4-D treatment included loss of normal bands and appearance of new bands in comparison to that of the control seedlings. Genomic template stability (GTS), carried out for the qualitative assessment of alterations in RAPD profiles, was also significantly affected by increasing concentrations of 2,4-D. (C) 2012 Elsevier B.V. All rights reserved.