The cytokinesis-block micronucleus (CBMN) assay is a common method for detecting genotoxicity in vitro, specifically the chromosome damage in cultivated cells. The fragments resulting from chromosomal breakage or mis-segregation during mitosis, leads to the development of micronuclei in the dividing cells. These micronuclei go unnoticed as they don’t segregate with either of daughter nuclei, rather they exhibit independent appearance within the cytoplasm of dividing cell. Therefore, it would be easy to trap the micronuclei by blocking cytokinesis, since karyokinesis precedes cytokinesis. The CBMN assay uses Cytochalasin-B to stop cytokinesis, which ensures that only dividing cells are examined, boosting its accuracy and reliability. The assay is sensitive to a variety of genotoxic agents, including chemical mutagens, radiation, and environmental pollutants. This makes it an important tool in genetic toxicology, biomonitoring, and medication safety assessment. Additionally, indicators such as nucleoplasmic bridges and nuclear buds seen within CBMN cells shed light on DNA damage and repair pathways. The CBMN assay is simple, cost effective and has a strong association with in vivo genotoxicity testing. This makes it the preferred method for early-stage screening of possible genotoxic chemicals in pharmaceutical and environmental investigations.