In this study, the effect of TiO2 nanoparticles (concentrations of 0, 5, 50, 100, 150 and 200 mg/l) on cytogenetic indices of cell devision and physiological responses of chickpea genotype (Sel96Th11439) was investigated. There was no chromosomal abnormalities in the control samples, and the mitotic index was 25%. By increasing the concentration of nanoparticles, the amount of mitosis index decreased (except for 25 mg/l TiO2, which showed the most increase). The lowest amount of mitosis index (14%) was found at 200 mg/l TiO2, which showed significant different compared to control samples. The effect of TiO2 nanoparticles on the mitotic index, chromosomal deviation index and anaphase index was significant whereas the metaphase and telophase indices did not show significant difference. There were no metaphase, anaphase, and telophase abnormality in control samples as well as at concentrations up to 50 mg/l, while at the concentration of 100, 150 and 200 mg/l, telophase, anaphase, metaphase and telophase abnormalities were observed, respectively. At lower concentrations of TiO2 (5 mg/l), there was not significant differences in cytogenetic and physiological indices compared to the control plants. Due to sever damages the mitosis index decreased at 100 mg/l of TiO2. It seems that at high concentrations of TiO2, ROS accumulation undermined organelles and DNA, led to chromosomal abnormalities and a decrease in mitosis index.