Background: Plasminogen activator inhibitor 1 (PAI-1) was previously established to impact several phenotypes in many kinds of cancer, including pancreatic cancer. However, its prognostic significance in pancreatic ductal adenocarcinoma (PDAC) needs support of further evidence. This study was designed to address the issue. Methods: PAI-1 expression was detected by tissue microarray-based immunohistochemical staining in formalin-fixed paraffin-embedded specimens from 93 PDAC patients with surgical resection from September 2004 to December 2008. Its relationships with clinicopathologic variables and tumor-specific survival (TSS) were further evaluated using Chi-square, Kaplan-Meier, log-rank, as well as Cox regression analyses. Results: Expression of PAI-1 was much higher in tumor than that in nontumor tissues, based on comparison of all samples and 74 matched ones (95 [47.5, 180] vs. 80 [45, 95], Z = ?2.439, P = 0.015 and 100 [46.9, 182.5] vs. 80 [45, 95], Z = ?2.594, P = 0.009, respectively). In addition, tumoral PAI-1 expression was positively associated with N stage (22/35 for N1 vs. 21/51 for N0, χ2 = 3.903, P = 0.048). Univariate analyses showed that TSS of patients with high PAI-1 tumors was significantly poorer than that of those with low PAI-1 tumors (log rank value = 19.00, P < 0.0001). In multivariate Cox regression test, PAI-1 expression was identified as an independent predictor for long-term prognosis of resectable PDAC (hazard ratio = 2.559, 95% confidence interval = 1.499–4.367, P = 0.001). Conclusion: These results suggest that expression of PAI-1 is upregulated in PDAC and might serve as a poor prognostic indicator.