In this work, the cytotoxic and genotoxic influences of oxyfluorfen herbicide were surveyed by examining of mitotic index, mitotic stages, chromosomal anomalies, micronucleus percentage, and comet assay parameters on the somatic cells of Allium cepa. The roots were treated with 0.2, 0.4, 0.8 and 1.6 ppm herbicide concentrations with 12, 24 and 36 h. application periods. Mitotic index was noticeably diminished by oxyfluorfen in each application group when matched with their control, except for 0.2 ppm. The percentages of mitotic stages were altered. Oxyfluorfen enhanced drastically the aberrant cell ratio at all application groups and application periods in contrast to their control, excluding 0.2 ppm. Mitotic anomalies were noted as disturbed prophase, stickiness, C-mitosis, chromatid bridges and laggards. The micronucleus was detected at interphase and its percentage was determined in the applied concentrations. Also, the comet assay was employed to examine the single strand breakages. Almost all of the used concentrations of oxyfluorfen increased DNA losses. A positive relationship was discovered between micronucleus occurrence and DNA loss.