The aim of this study was to evaluate whether neoadjuvant therapy (NAT) critically influenced microscopically complete resection (R0) rates and long-term outcomes for patients with pancreatic ductal adenocarcinoma who underwent pancreatoduodenectomy (PD) with portomesenteric vein resection (PVR) from a diverse, world-wide group of high-volume centers. Limited size studies suggest that NAT improves R0 rates and overall survival compared to upfront surgery in R/BR-PDAC patients. This multicenter study analyzed consecutive patients with R/BR-PDAC who underwent PD with PVR in 23 high-volume centers from 2009 to 2018. Data from 1192 patients with PD and PVR were collected and analyzed. The median age was 68 interquartile range (IQR) 60-73 years and 52% were males. Some 186 (15.6%) and 131 (10.9%) patients received neoadjuvant chemotherapy (NAC) alone and neoadjuvant chemoradiotherapy, respectively. The R0/R1/R2 rates were 57%, 39.3%, and 3.2% in patients who received NAT compared to 46.6%, 49.9%, and 3.5% in patients who did not, respectively (P =0.004). The 1-, 3-, and 5-year OS in patients receiving NAT was 79%, 41%, and 29%, while for those that did not it was 73%, 29%, and 18%, respectively (P <0.001). Multivariable analysis showed no administration of NAT, high tumor grade, lymphovascular invasion, R1/R2 resection, no adjuvant chemotherapy, occurrence of Clavien-Dindo grade 3 or higher postoperative complications within 90 days, preoperative diabetes mellitus, male sex and portal vein involvement were negative independent predictive factors for OS. Patients with PDAC of the pancreatic head expected to undergo venous reconstruction should routinely be considered for NAT.