10.22376/ijpbs.2019.10.1.p1-12 Volume 12 Issue 1 2021 (January-March) Cyclophosphamide is an alkylating agent, and it comes under the category of Nitrogen mustards, used in treatment of cancer. It disturbs cell proliferation, particularly DNA Synthesis, which provides the basis for its therapeutic use. The dosage per oral (PO) administration is 400-1000 mg/m² divided over 4-5 days to treat malignant cancer. () Malignant cells (cancer cells) present with a mutant or absent p53 gene which fails to stop cell cycle multiplication and not allow the tissue to undergo apoptosis. i.e, cells are not dying after their normal life span and therefore the cells multiply unlimitedly leading to the formation of tumor. ( it is generally agreed that Nitrogen mustards inter strand cross-linking of DNA associated with Cytotoxicity. "cyclophosphamide inter strand cross linkage of DNA leading to retardation of cell division". cellular responses include cell death. In the present study one set of fertilized eggs were administered with cyclophosphamide after 24 hours of incubation and another set of eggs were kept as control. The objective of the study is to determine the neural cell multiplication after administering of drug cyclophosphamide. The development of the neural tube of chick embryo was studied. The gross features of embryo were identified. Cyclophosphamide causes depression of cell multiplication in the nervous tissue leading to malformations which often result in embryonic death. The safety of drug to be administered during pregnancy has been studied. As it depresses the growth of nervous tissue hence it's proved that the administration of the drug is not safe during early weeks of pregnancy which is generally prescribed due to prevalence of cancers in young females. Dr. Amrutha Roopa Ramagalla, Dr. Shabana Sulthana and Mr. Mohd Fazal Cell death, Cell division, Chick embryo, Cyclophosphamide (CP), DNA, Fertilized eggs, Neural tube 79-84