Objective measures of post-pancreatectomy weight change for pancreatic ductal adenocarcinoma (PDAC) have not been extensively studied for long-term outcomes. We used weight measurements in our institutional medical record to analyze trends in post-pancreatectomy weight and determine the association with disease status. Pancreatectomies for PDAC (n = 315) and benign indications (n = 111) were identified. Preoperative baseline, minimum postoperative (Min #1), and subsequent postoperative maximum (Max) weights were abstracted. Multivariable Cox hazards regression was conducted to analyze the association between weight change and survival. Median weight loss postoperatively in each group was > 20 lbs. PDAC patients gained 10 lbs after Min #1 compared to 15 lbs in the benign cohort (p < 0.001). Few patients returned to their preoperative weight (29.8% PDAC vs. 40.5% benign, p = 0.04). Patients with early PDAC recurrence (< 13 months) lost more weight (18.0% vs. 13.3% vs. 10.9%, p < 0.001) and gained less weight (2.1% vs. 12.0% vs. 7.9%, p < 0.001) compared with those with late cancer recurrence (≥ 13 months) or no evidence of active disease, respectively. PDAC patients lost 11.2 lbs in the year preceding recurrence diagnosis. Weight loss was not associated with survival; however, weight gain was associated with improved survival. Resections for PDAC are complicated by a similar degree of weight loss as patients with benign disease, and there is no association with survival. However, failure to gain weight is especially ominous. Weight loss after weight recovery foreshadows disease recurrence. These data suggest that rigorous weight tracking is an untapped surveillance strategy in patients with PDAC.