This study was conducted to identify any possible association between the different microorganisms within oral cavity of smokers and oral cancer patients. Isolates were collected from 30 volunteers; smokers and oral cancer patients during August and October 2013 in Khartoum Dental Hospital, Sudan. Swabs were obtained from both patients and smokers who were not diagnosed as diabetics or immunosuppressed. Administration of antibiotic, steroid or other treatment were taken in concern as well as age, gender beside smoking history. Each specimen was aseptically cultured on nonselective media under both aerobic and anaerobic conditions, then the conventional methods for identification were done. A total number of 45 bacterial isolates were represented by 6 genera of bacteria; (37.7%) Staphylococcus spp, (26.6%) Bacillus spp , (22.2%) Streptococcus spp , (8.8%) Peptococcus spp., Aerococcus spp and Micrococcus spp (2.2%), whereas 25 yeast isolates were represented by Candida albicans. In the smokers group; Peptococcus spp was detected only in subjects who is being smoking. Moreover, the study showed significant(r = 0.563) correlation between oral cancer and smoking. In patients group; Streptococcus spp and C. albicans were detected only in individuals without treatment. Counts of C. albicans were elevated in smokers group than patients, while, Micrococcus spp and Aerococcus spp were detected in patients but not in smokers. Study concludes that both of Micrococcus spp and Aerococcus spp may be considered as diagnostic indicators of oral cancer.