Ethylenediaminetetraacetic acid (EDTA) has many applications in plant research in addition to other applications, such as chelation and medical therapy. The morphological and cytogenetic effects of EDTA on barley seedlings were investigated in the present study. Seeds of Hordeum vulgare L. were treated with different doses of EDTA (30, 60, 90, 120 and 150 mmol/l) and 2 different application periods (20 and 22 h). Except mitotic index, all of the measurements for the investigated characters were carried out on days 7 and 14. EDTA treatments affected germination rates in nearly all treatments. In general, EDTA treatments decreased the root, leaf and coleoptile lengths, but it had the greatest effect on coleoptile length. Increasing the EDTA dosages and treatment periods also decreased the mitotic index compared to the untreated control. The inhibitory effects of EDTA dosages on the mitotic index indicate that EDTA can have genotoxic and mutagenic effects on barley seedlings. © TÜBİTAK.