10.22376/ijpbs.2019.10.1.p1-12 Volume 2 Issue 3 2011 (July - September) Pan Masala (PM) chewing is very dangerous for health but it is becoming very popular day by day. PM is a dried powdered mixture containing ingredients like areca nut, catechu, lime, cardamom and flavouring agents. It is consumed abundantly by Indians and is also exported to Western countries. A cytogenetic study to assess the micronucleus (MN), sister chromatid exchange (SCE) levels and chromosomal aberrations among (CA) 60 pan chewers and 60 non-chewers was conducted in Chennai, Tamil Nadu. In the present cytogenetic monitoring study, analysis of MN was significantly higher (15.82 ± 1.31) in chewers than controls (4.82 ± 1.47) (P lessThan 0.001) and SCE also was significantly higher in chewers (9.23± 2.12) than controls (4.80±1.11) (P lessThan 0.001). In exfoliated buccal mucosa and chromosome analysis (CA), frequency of chromatid type aberrations is lower in controls than chewers such as gaps (0.90% v. 1.83%) breaks (0.47% v. 1.77%), exchanges (0.02% v. 0.18) and acentric fragments (0.20% v. 0.90%). The increased percentage of aberrations found among pan chewers is significantly higher when compared to that of the controls. Isochromatid aberrations also increased significantly such as gaps (0.12% v. 0.97%) breaks (0.07% v. 0.80%), acentric fragments (0.05% v. 0.23%), dicentrics (0.02% v. 0.63%), and these were estimated in the peripheral blood lymphocytes to assess possible DNA damage. All three cytogenetic endpoints demonstrated a statistically significant increase (P lessThan 0.001) among the pan masala chewers as compared with the non-consuming controls. In conclusion, we propose the use of the cytokinesis-block micronucleus assay, sister chromatid exchange and chromosome aberrations for getting a sensitive information on cell cycle progression and cytotoxicity of chewing pan masala. V. Ramakrishnan, S. Gowtham Kumar And S. Govindaraju Micronuclei, Chromosome aberration, Sister chromatid exchange, Pan masala, Buccal mucosa. 122-134