Purpose To determine if prophylactic suction using a Freka nasojejunal tube, after oesophagectomy and gastrectomy, reduces incidence of anastomotic leaks. Methods We performed a retrospective observational cohort study on patients who underwent oesophagectomy and gastrectomy with primary anastomosis between 2012 to 2023, across two major tertiary centres. Prophylactic suction was applied at 5kpa. Data collected include patient demographics, background medical history, operative outcomes, severity and timing of anastomotic leaks. Results were analysed using SPSS v25.0 (SPSS, IBM Corp, Armonk, NY). Results 354 patients underwent oesophageal anastomosis with Freka insertion, majority (65.3%) underwent 2-stage oesophagectomies, 24.9% gastrectomies, and 9.9% 3-stage oesophagectomies. Average age was 64.4±10.0 years, with majority (83.3%) male. 61.9% received prophylactic suction. Incidence of leaks was 10.2%, with majority (52.8%) being grade 2. Prophylactic suction was associated with reduced incidence of leaks, although not statistically significant. Use of prophylactic suction was significantly associated with reduced ICU and overall length of stay (LoS). The occurrence of leaks is associated with morbidities of atrial fibrillation and pneumonia, increased 30-day mortality, as well as increased LoS. Risk factors in our cohort for increased leaks include smoking, previous IHD, higher post-operative white cell count (WCC) and longer operation time. After adjusting for prophylactic suction, smoking, IHD and prolonged operation times were no longer statistically significant. Conclusion Prophylactic suction may reduce post-operative anastomotic leaks in high-risk patients with prolonged operative times, IHD and a smoking history.