Introduction: People with diabetes frequently have gastrointestinal problems and related deglutition disorders. Objective: The aims of the present study are to determine the symptomatic swallowing complaints and to evaluate the functionality of oropharyngeal swallowing in patients with type 2 diabetes mellitus (T2DM) by using the Turkish Eating Assessment Tool-10 (T-EAT-10) and fiberoptic endoscopic evaluation of swallowing (FEES). Methods: In this descriptive cross-sectional study, the T-EAT-10 questionnaire was completed by 121 patients with diabetes, and FEES was planned for each individual whose baseline score of the T-EAT-10 was >= 3. Before swallowing trials via samples of nectar-thick consistency, laryngeal sensation and severity of secretion in the hypopharynx were observed. While the swallowing safety was determined using the Penetration-Aspiration Scale (PAS), the Yale Pharyngeal Residue Severity Rating Scale was used to assess the swallowing efficiency. Results: Of the total participants, 22.3% (n = 27) were found to have abnormal swallowing function (T-EAT-10 >= 3), 27.3% (n = 33) had concomitant neuropathy and 28.1% (n = 34) mentioned a reflux complaint. The results of the multivariate linear regression analysis exposed that the T-EAT-10 score was significantly associated with neuropathy (r = 3.763, p < 0.001) and reflux complaint (r = 2.254, p = 0.031). Of the total FEES-tested subjects (n = 20), 95% (n = 19) had a safe swallowing function (PAS = 1). However, diminished laryngeal sensation, increased secretion and presence of residue revealed that patients with T2DM who have self-reported swallowing difficulties have reduced swallowing efficiency. Conclusions: This study has demonstrated that almost 1 out of 4 T2DM patients reported to have swallowing-related problems, and the score of the T-EAT-10 was found to be independently associated with both neuropathy and reflux complaint. FEES results pointed out that swallowing efficiency was relatively reduced in the target population. However, further research is still necessary before obtaining a definitive answer to oropharyngeal swallowing problems in patients with T2DM.