Background: Benzene, which is a major organic product, on chronic exposure can result in many malignant disorders, and therefore exposure to gasoline vapors is classified by the International Agency for Research of Cancer as possible carcinogenic to humans. Petrol station attendants are chronically exposed to petroleum derivatives through inhalation of petrol during vehicle refuelling. Aim: This study is aimed to investigate cytogenotoxic damage in exfoliated buccal cells obtained from petrol station workers and control subjects using micronucleus (MN) test. Materials and Methods: This study was carried out on 30 petrol station attendants working at different petrol stations located in Indore. The control group consisted of 30 healthy subjects who were not exposed to benzene. Buccal cell samples were collected at the end of the work shift. Slides were stained and were evaluated to determine the MN frequencies. Exposure monitoring was performed by the detection of phenol excreted in the urine. Urinary phenol measurements were performed following the colorimetric quantitative determination method of Yamaguchi and Hayashi. Results: Variations in MN frequencies were seen in control and petrol bunk attendants. Conclusion: The MN test in exfoliated epithelial cells seems to be a useful biomarker of occupational exposure to genotoxic chemicals. Phenol is the principal metabolite of benzene. Therefore, phenol concentration in the urine of exposed workers can be used as a biomarker of external exposure.