Background Data supporting the routine use of adjuvant chemotherapy (AC) compared with no AC (noAC) following neoadjuvant chemotherapy (NAC) and resection for pancreatic ductal adenocarcinoma (PDAC) are lacking. This study aimed to determine whether AC improves long-term survival in patients receiving NAC and resection. Methods Patients receiving resection for PDAC following NAC from 2004 to 2016 were identified from the National Cancer Data Base (NCDB). Patients with a survival rate of Results Of 4449 (68%) noAC patients and 2111 (32%) AC patients, 2016 noAC patients and 2016 AC patients remained after PSM. After matching, AC was associated with improved survival (median 29.4 vs. 24.9 months; p p p p p p = 0.007), no neoadjuvant radiotherapy (NART; HR 0.84, 95% CI 0.74–0.96; p = 0.009), and use of NART (HR 0.80, 95% CI 0.73–0.88; p Conclusion AC following NAC and resection is associated with improved survival, even in margin-negative and node-negative disease. These findings suggest completing planned systemic treatment should be considered in all resected PDACs previously treated with NAC.