Introduction: Diabetes as one of the most important disease of this century, causing problems and complications in the patients; of this complication are dental problem including dental caries. Given the lack of studies in these patients, this study aimed to "determining the DMFT index and its correlation with the Blood Sugar and HbA1c levels in diabetic patients in Ahvaz at 2016-2017". Materials and Methods: This descriptive-analytic and cross sectional study was done in 2016-17, with participating of 245 type 2 diabetic patients that referred to hospitals of Ahvaz. Then DMFT index, Blood Sugar (BS) and HbA1c were surveyed in the patients. Results: The mean and standard deviation of DMFT index in the patients were 15.51 and 7.86 respectively. Also, there are a significant correlations between DMFT index and BS levels and age in the samples (P< 0.001). But, there aren't any significant correlations between DMFT index and HBA1c levels(P> 0.05). Conclusion: Given the importance of oral health in general improving of quality of life of diabetic patients and, given the results of this study showed that these patients are not in good condition in terms of dental health, educating patients and their families regarding the more use of dental services and dental and oral hygiene, is recommended.