Cyclophosphamide (CPA) is a nitrogen alkylating agent used for various types of cancer & some autoimmune diseases. It is a prodrug that is converted to its active metabolites in liver. At higher doses, it interrupts cell cycle by forming DNA cross linking, DNA lesions. It mediates G0/G1 and S phase arrest. At chromosomal level, this anti-neoplastic drug causes chromosomal aberration(CA) and increase in frequency of sister chromatid exchange (SCE). It also causes apoptosis and cell toxicity. Due to its wider clinical use, study of its genotoxicity has significant practical aspect. In this present study the chemoprotective effect of Chenopodium album extract was tested against the genotoxicity induced due to Cyclophosphamide (CPA) in human lymphocytes using chromosomal abberations (CA) as a parameter. About 100 μg/ml of CPA was treated with Chenopodium album extract at dosages of 3,6,9 mg/ml.A dose dependent decrease in genotoxic damage of CPA was observed. So the result clearly suggests the modulatory potential of Chenopodium album against the genotoxicity of CPA in-vitro.