Background: Periodontal disease (PD), now our commonest infectious disorder leads to tooth loss, and has been linked to various systemic diseases, including various types of cancer. The aim of this study is to provide a systematic review and a meta-analysis of the relationship between PD, edentulism, and pancreatic cancer (PC). Patients and methods: From an initial review of 327 references we selected eight studies concerning periodontitis or edentulism with sufficient quantitative information to allow us to examine the risk of PC. We used relative risks (RRs), hazard ratios, or odds ratios to measure the association between periodontitis, edentulism, and PC. We employed random effects models to obtain summary risks, and we also provide measures of study differences and possible biases. Results: The summary RR for periodontitis and PC was 1.74 [95% confidence interval (CI) 1.41-2.15] and 1.54 for edentulism (95% CI 1.16-2.05). There was no evidence of heterogeneity for either variable, and no evidence of publication bias. The studies included reports from three continents, suggesting that the association is generalizable. Most of the studies were adjusted for variables thought to be associated with PC, such as gender, smoking, BMI, diabetes, and alcohol. Conclusions: Using meta-analysis, both periodontitis and edentulism appear to be associated with PC, even after adjusting for common risk factors. As yet, the mechanisms linking oral disease and PC are uncertain, but could be related to changes in the oral microbiome-an area of current research.