The role of adjuvant radiotherapy in patients with microscopically positive circumferential resection margins (CRM), R1 specimen, in oesophageal resections for cancer with curative intent remains unclear. However, R1 specimens are associated with poorer survival outcomes. The aim was to assess the benefit of adjuvant radiotherapy on recurrence and survival in these patients. Patients were identified in a single centre between July 2000 and December 2016. Patient demographics, tumour characteristics and survival outcomes were assimilated and compared between those who received adjuvant therapy and those who did not. Sixty-eight patients were included in the study; 57 (83.8%) male and 11 (16.2%) female with a median age of 67 years. The adjuvant radiotherapy regimen used was 40-50 Gy in 25 fractions over 5 weeks. Median follow-up was 13 months (interquartile range, 6-27 months). Twenty-five (36.8%) patients received adjuvant radiotherapy. There was no statistically significant correlation between administration of adjuvant radiotherapy and local recurrence (P=0.148), distant metastases (P=0.605), overall disease progression (P=0.561), progression-free survival (P=0.663) and overall survival (P=0.538). This study detects no benefit to oncological outcomes with the use of adjuvant radiotherapy in patients with microscopically positive CRM. Larger randomized studies are needed to further confirm these results.