(1) Background: Currently available guidelines require upper gastrointestinal (GI) endoscopy with biopsy sampling for adult celiac disease (CD) diagnosis. Based on the pediatric experience, there has been a growing interest if serology-based diagnosis would be possible for adult CD also. Our aim was to analyze the associated upper GI tract lesions in newly diagnosed CD patients, to see if significant associated pathology is detected during index endoscopy, which might impact patient management not related to CD. (2) Methods: We performed a retrospective analysis of newly diagnosed CD cases diagnosed over a period of 7 years (2014–2020). Demographic, clinical, laboratory, endoscopy and histopathology data were collected from the patients’ charts. Diagnosis was set according to ACG Guideline 2013. (3) Results: Altogether 79 patients were recruited for this study purpose, 75.9% female, median age 39 years. All patients had positive CD-specific serology and atrophic mucosal injury in duodenal biopsy samples. Besides villous atrophy, associated endoscopic findings were detected in 42/79 (53.16%) of patients. Most of the gastric lesions were minor endoscopic findings—small sliding hiatal hernias, non-specific chronic gastritis, but we also found two cases of peptic ulcers, one case of metaplastic gastritis, six cases of atrophic gastritis and one subepithelial lesion. Only one patient had changes in the duodenum except CD-related findings—an inflammatory polyp in the duodenal bulb. No malignancies were found. (4) Conclusions: In our cohort, there was a significant number of newly diagnosed CD patients who had associated lesions during the index upper GI endoscopy, but most of them were minor endoscopic findings. View Full-Text ►▼ Show Figures This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited