Purpose: To determine the resistance & sensitivity of the subgingival microflora against antimicrobial agents in untreated adult healthy & diabetic patients with chronic periodontitis. Materials and Method: A comparative study comprises of the two population healthy & diabetics, diagnosed as chronic periodontitis. Total 60 patients with chronic periodontitis were selected for the study & divided in 2 groups – Healthy & Type II diabetes. Subgingival plaque samples were collected from all the patients & culture & sensitivity test was done for various antibiotics– Amoxicillin, Amoxiclav, Metronidazole, Cefixime, Tetracycline& Ciprofloxacin. Results: Statistical analysis was done. In diabetic patients results revealed more resistance for Metronidazole (83.3%) & least for Tetracycline (16.7%) while healthy patients showed more resistance for Metronidazole (60%) & least for Tetracycline (3.3%) & Ciprofloxacin (3.3%). Significant results were found for Metronidazole & Ciprofloxacin resistance between two groups. Conclusion: The current results showed alarmingly high resistance rate against Metronidazole. However, misuse of these agents in our city is huge. The emergence of antibiotic resistant bacteria within the oral flora will have an impact on the prescribing of antibiotic in dentistry