Abstract :Aim:The aim of this study was to associate plaque and periodontal diseases among outpatients. Materials and methods:This was a comparative, descriptive study, where all the data of the patients who reported to the dental clinics in saveetha dental college, SIMATS, Chennai, India, was obtained from the department of public health dentistry. Patient records of plaque index score and periodontal index scores between June 2019 and March 2020. were reviewed and analysed from April - June, 2020. Data was collected and tabulated. The collected data was further analyzed, recorded in microsoft excel software and was subjected to statistical analysis using IBM SPSS statistics analyzer.Results: The total sample size of the current study was 158 cases. The most common age group that was observed was 36 to 50 years with 43.7 %. A male predilection was seen with males making up 63.9 % of the study population. Most commonly seen periodontal index score interpretation was established destructive periodontal disease with 51.9 %. Most prevalent plaque score interpretation was a fair plaque score with 55.1 % of the population. It was also observed that a fair plaque score was more commonly present in established destructive periodontal disease in 59.7 % of the cases. In this study we observed that there was a significant relation between the plaque and periodontal index scores among outpatients. [p value < 0.05 ] [ p = 0.008] obtained through chi square test. Conclusion:Within the limitations of the current study, we observed that fair plaque score was found to be more common prevalent among participants with established periodontal disease and this association was not statistically significant.