Trefoil factor family protein 1 (TFF1, pS2) interacts with mucins to protect gastrointestinal epithelium against injury and contributes to mucosal repair by promoting epithelial cell migration and restitution. Moreover, TFF1 has antiproliferative and anti-apoptotic effects and promotes cell scattering and invasion. We investigated TFF1 expression in healthy and inflamed non-neoplastic gallbladder mucosa as well as in gallbladder carcinomas (n=57) and corresponding metastases (n=18), using a tissue microarray technique. TFF1 immunoreactivity was absent in healthy mucosa, focally observed in epithelium with inflammatory changes and present in 35% of primary and 24% of metastatic cancer tissues. Immunoreactivity significantly decreased with increasing tumour stage (P=0.009) and increasing tumour grade (P=0.001). Patients with TFF1 positive tumours showed a more favourable outcome compared to patients with TFF1 negative tumours in univariate analysis (P=0.006). However, multivariate analysis proved resection status and tumour grade as the only independent prognostic factors. In conclusion, TFF1 is expressed in inflamed non-neoplastic gallbladder epithelium and in low stage and low grade gallbladder carcinomas. Thus, TFF1 may be the missing link between gallstones, chronic cholecystitis and gallbladder cancer. Further studies are needed to evaluate whether TFF1 immunostaining can be used as a diagnostic tool to identify patients with a more favourable outcome.