Introduction: The diagnosis and classification of megaesophagus can be challenging in patients with Chagas disease. The present study aimed to evaluate the agreement between upper endoscopies and esophagographies for the diagnosis and classification of megaesophagus in Chagas disease. Methods: A cross-sectional study of 50 patients with Chagas disease with upper digestive symptoms was undertaken. Esophagography and upper endoscopy exams were performed to compare diagnoses. Statistical analysis included sensitivity and specificity used to evaluate the diagnostic accuracy of upper endoscopies, and measures of agreement: linearly weighted Kappa (κw) and Cohen`s classical Kappa (κ) coefficients with 95% confidence intervals (95% CI). Results: Twenty-three patients (46%) were diagnosed with megaesophagus by esophagography. The upper endoscopy sensitivity and specificity for megaesophagus diagnosis were 100% and 33.3%, respectively. Regarding megaesophagus classifications, there was a substantial agreement between the two exams (κw = 0.622; 95% CI: 0.498 to 0.746). Within megaesophagus groups, agreement for group I wasslight (κ = 0.096; 95% CI: 0.000 to 0.403); for group II,substantial (κ = 0.703; 95% CI: 0.456 to 0.950); and for groups III and IV, inconclusive (κ = 0.457; 95% CI: 0.000 to 0.967; κ = 0.540; 95% CI: 0.035 to 1.000, respectively). Conclusions: Upper endoscopy has a high sensitivity, but a low specificity to diagnose megaesophagus. Agreement between the two exams varies depending on the megaesophagus grade. Thus, upper endoscopy can be used in the diagnostic workup of a possible Chagas disease megaesophagus, but all identified cases should undergo esophagography.