Objective Intrathoracic anastomotic leakage after intended curative resection for cancer in the esophagus or gastroesophageal junction has a negative impact on long-term survival. The aim of this study was to investigate whether an anastomotic leakage was associated with an increased recurrence rate. Methods This nationwide study included consecutively collected data on patients undergoing curative surgical resection with intrathoracic anastomosis, alive 8 weeks postoperatively, between 2003 and 2011. Patients with incomplete resection, or metastatic disease intraoperatively, were excluded. Only biopsy-proven recurrences were accepted. Results In total, 1085 patients were included. The frequency of anastomotic leakage was 8.6%. The median follow-up time was 29 months (interquartile range [IQR]: 13-58 months). Overall, 369 (34%) patients had disease recurrence, of which 346 patients died of recurrent gastroesophageal carcinoma. Twenty-three patients were alive with recurrence at the censoring date. In the study period, 333 patients died without signs of recurrent disease. The overall median time to recurrence was 66 weeks (IQR: 38-109 weeks). Distant metastases were found in 267 (25%), and local disease recurrence in 102 (9%) patients. Overall, 5-year disease-free survival in patients with leakage was 27%, versus 39% in those without leakage (P =.017). Anastomotic leakage was independently associated with higher risk of recurrence (hazard ratio [HR] = 1.63; 95% confidence interval [CI]: 1.17-2.29, P =.004) and all-cause mortality (HR = 1.57; 95% CI: 1.23-2.05, P <.0001). Conclusions Intrathoracic anastomotic leakage increased the risk of recurrence in patients who underwent curative gastroesophageal cancer resection.