Objective: To investigate the expression of syndecan-1 and syndecan-2 and their clinicopathological significance in patients with gallbladder squamous cell (SC)/adenosquamous carcinoma (ASC) and adenocarcinoma (AC). Methods: A total of 126 patients with SC/ASC (n=46) and AC (n=80) were included in this study. The expression levels of syndecan-1 and syndecan-2 were detected by Envison™ immunohistochemistry assay. The clinical and prognostic significance of syndecan-1 and syndecan-2 were analyzed. Results: In the 46 SC/ASC samples, syndecan-1 and syndecan-2 were positively expressed in 29 (63.0%) and 28 (60.9%) tumor tissues, respectively. (Positive expression was defined based on the staining in the component of squamous cell carcinoma. That is to say, the tissue which adenocarcinoma part was positively stained, but squamous cell carcinoma part was negatively stained is also regarded as negative.) In the 80 AC samples, 47 (58.8%) cases showed syndecan-1 positive expression, and 51 (63.8%) showed syndecan-2 positive expression. There was no significant difference in the positive rates of syndecan-1 and syndecan-2 between SC/ASC and AC groups (P>0.05 for all). The levels of syndecan-1 and syndecan-2 were associated with tumor size, TNM staging, lymph node metastasis, invasion of adjacent tissue, and surgical procedures in SC/ASC patients (P<0.05 for all). However, their expression was associated with tumor differentiation, tumor size, TNM staging, lymph node metastasis, invasion of adjacent tissue, and surgical procedures in AC patients (P<0.05 for all). The Kaplan-Meier survival analysis of SC/ASC and AC patients revealed that the average survival time for patients with positive syndecan-1 and syndecan-2 expression was significantly shorter than that of those with negative expression (P<0.01 for all). Cox multivariate analysis indicated that syndecan-1 and syndecan-2 expression were independent unfavorable prognostic factors for SC/ASC and AC patients (P<0.05 for all). Conclusion: The syndecan-1 and syndecan-2 expression are associated with the tumor progression and poor prognosis in patients with gallbladder SC/ASC and AC.