New-onset atrial fibrillation (AF) is frequently observed following esophagectomy and may predict other complications. The aim of the current study was to determine the association between, and the possible predictive value of, new-onset AF and infectious complications following esophagectomy. Consecutive patients who underwent elective esophagectomy with curative intent for esophageal cancer between 2004 and 2016 in the University Medical Center Utrecht were included from a prospective database. The date of diagnosis of the complications included in the current analysis was retrospectively collected from the computerized medical record. The association between new-onset AF and infectious complications was studied in univariable and multivariable logistic regression analyses. A total of 455 patients were included. In 93 (20.4%) patients new-onset AF was encountered after esophagectomy. There were no significant differences in patient and treatment-related characteristics between the patients with and without AF. In 9 (9.7%) patients, AF was the only adverse event following surgery. In multivariable analyses, AF was significantly associated with infectious complications in general (OR 3.00, 95% CI: 1.73-5.21). More specifically, AF was associated with pulmonary complications (OR 2.06, 95% CI: 1.29-3.30), pneumonia (OR 2.41, 95% CI: 1.48-3.91) and anastomotic leakage (OR 3.00, 95% CI: 1.80-4.99). In patients who underwent esophagectomy, new-onset AF was highly associated with infectious complications. AF may serve as an early clinical warning sign for anastomotic leakage. Therefore, further evaluation of patients who develop new-onset AF after esophagectomy is warranted.