In a prospective randomized double-blind study, we evaluated the post-operative biological and clinical effects of a single preoperative hyperbaric-treatment the day before surgery for pancreatic ductal adenocarcinoma. Patients and Methods: Twenty one patients were randomized and divided into two groups: group-A (10 patients, 48%) were exposed to a HyperBaric Oxygen (HBO) session the day before intervention [Pre-Intervention Day (PID)], group-B (11 patients, 52%) breathed air for 40 min in a hyperbaric chamber pressurized to 1.15 ATA (placebo group). For all patients blood samples were obtained before HBO treatment or the placebo procedure (T0); at the end of HBO session or placebo procedure (T1); on the first post-operative day (POD)(T2) and on seventh POD(T3) day, measuring interleukin (IL)-1, IL-6, IL-8, IL-10, IL-12 and TNF-α, recording postoperative pancreatic fistula (POPF), biliaryfistula, fever, intra-abdominal abscess, bleeding, pulmonary complications, delayed gastric emptying and requirement for post-operative antibiotics. The results of the present pilot study suggest that a single preoperative hyperbaric oxygen treatment on the day before surgery may reduce the complication rate in pancreatic resection.