eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2015-04-28 12 1 263 267 5412 article V. Shankar Ram 1 Lakshmi Narayanan 1 Umasudhakar 1 Thamizh Chelvan 1 Parthiban 1 Thai Moogambigai Dental College, Goldengeorge Nagar, Chennai - 600107, India. Oral cancer is the sixth most common malignancy worldwide and ranked third of all cancers in india.90% of cancers in oral cavity are Squamous cell carcinomas originating from the oral mucosa. Majority of case of oral cancer can be related to tobacco use and tobacco smoking.Other risk factors include viral,bacterial infections, poor oral hygiene and candidalinfections.Association of bacteria with oral tumours and its relationship of smoking with oral bacterial flora is of increasing interest.Most important etiological factor of oral squamous cell carcinoma is smoking.Smoking also being a risk factor for chronic periodontitisRecently it has been reported that patients with oral SCC (OSCC) tend to possess significantly raised concentrations of certain specific pathological bacteria in saliva. This research article we will see the prevalence of micro-organisms from the plaque in patients with oral malignancy with or without smoking https://www.biotech-asia.org/vol12no1/microbiological-assessment-in-plaque-samples-of-patients-with-oral-cancer-with-or-without-smoking/ OSCC (oral squamous cell carcinoma); Tobacco smoking; Subgingival plaque