Curcumin is a yellow pigment produced from the rhizomes of the Curcuma longa plant and a primary chemo preventive component of turmeric is used as a spice and food coloring ingredient. Curcumin has a large number of pharmacological activities, such as anticancer, anti-diabetic, antioxidant, anti-infectious, and anti-inflammatory properties.Investigation of the geno-protective effect of curcumin on methotrexate induces chromosomal aberrations of spleen and bone marrow cells. In this study, 32 mice were used and divided into four groups (eight mice at each group) as follows: Group1 (negative control): Dimethyl sulfoxide was given intraperitoneally to mice every day for ten days.Group2 (positive control): Mice were received a single dose (20mg/kg) of methotrexate intraperitoneally Group3: Mice were received (200mg/kg) of curcumin solution intraperitoneally for ten successive days.Group4: Mice were received (200mg/kg) of curcumin solution intraperitoneally for ten successive days and on the day 11, a single dose  of methotrexate ( 20 mg/kg ) was injected intraperitoneally . In animals treated with methotrexate, significant elevations of the chromosomal aberrations were observed along with a decline in the mitotic index. Meanwhile, there was a considerable elevation of the mitotic index and no detectable chromosomal changes in the curcumin-supplemented mice. The number of abnormal cells was reduced significantly in the curcumin-treated group in comparison with the methotrexate-treated group. The ability of curcumin to inhibit methotrexate's cytotoxic effects was shown by the compound's ability to raise the mitotic index. According to this finding, curcumin approved to be a protective agent against genotoxic effects of methotrexate. Keywords: Curcumin, Chromosomal aberrations, Methotrexate, Mitotic index, Mice