Non-Surgical Root Canal Treatment (NSRCT) is performed to save the teeth with infected root canal system. A number of factors affect the long term survival of NSRCT. There is limited evidence correlating the survival rate of NSRCT in older adults with existing comorbid conditions and comparing them with the survival rate of NSRCT in younger adults. The primary objective of this study was to analyze the survival of non-surgical root canal therapy in older adults with comorbid conditions. Data was collected from patients' charts retrospectively to analyze the factors affecting the survival rate of NSRCT in permanent teeth in patients aged 18 and above and analyzed to compare the comorbid conditions in older adults and young adults. Factors including gender, prevailing coronary heart disease, diabetes, cancer, cancer therapy, and tobacco habits that may influence the long-term survival of endodontically treated teeth were analyzed statistically using a follow up data for five years. Survival analysis was the statistical method of choice to analyze the results given the focus of the clinical question on failure of endodontic treatment. Kaplan-Meier survival estimates were calculated for 5-year survival of endodontically treated teeth (with 95% confidence intervals). Teeth that had been retreatment, periapical surgery or extraction were considered as having had a complication, i.e., a failure. Analysis using the Kaplan-Meier method requires that actual date of failure (as indicated in description of project) as well as the date of initial endodontic treatment were available in the data set. The dates of re-treatment were considered as the date of failure for the purpose of statistical analysis. The statistical analysis showed that there was no significant association between age and root canal survival but there was a possible association between NSRCT failure and the presence of diabetes and tobacco habits.