In the present study, the cytogenetic effects of the herbicide roundup on division of root meristematic cells of Trigonella foenum graecum and influence of this treatment on height plants in early ontogenetic phase were studied. The seeds of plants were treated with various concentrations of roundup (0.1%, 0.5%, 1.0 %, and 2.0 %), for 3 and 6 h. Roundup had an inhibitory effect on plantlets height in early ontogenetic phases at all tested concentrations in 6 h treatment, comparatively with control, and at maximum tested concentration applied for 3 h. The mitotic index was significantly reduced by roundup 6h, for all tested concentrations. Roundup 3h, 0.1% and 1.0% variants, and roundup 6h, 0.5% and 2.0% variants induced the most numerous ana-telophase chromosomal aberrations. The presence of micronuclei and fragments suggests the potential clastogen effect of roundup.