Altered expression of TROP2 is observed in various types of human cancers. However, the clinical significance and pathological role of TROP2 in gallbladder cancer (GBC) remains unclear. The main objective of this investigation was to clarify the relationships between TROP2 expression and the clinicopathological features of patients with GBC. Immunohistochemistry was performed to investigate the expression of TROP2 and epithelial-mesenchymal transition (EMT) indicator proteins in 93 patients with GBC. Immunohistochemistry showed that the protein expression level of TROP2 was significantly higher in GBC tissues than in adjacent noncancerous tissues. In addition, immunohistochemistry analysis showed that TROP2 expression was significantly correlated with histologic grade (P=0.038), tumor stage (P=0.015), and lymph node metastasis (P=0.007). Furthermore, high TROP2 expression was significantly associated with a loss of the epithelial marker E-cadherin (P=0.013) and acquisition of expression of the mesenchymal marker vimentin (P=0.031). Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the correlation between TROP2 expression and prognosis of GBC patients. Kaplan-Meier analysis indicated that patients with high TROP2 expression had poor overall survival (P<0.001). Multivariate analysis showed that high TROP2 expression was an independent predictor of overall survival. In conclusion, our data suggest for the first time that the increased expression of TROP2 in GBC is associated significantly with aggressive progression and poor prognosis. In conclusion, this study confirmed that TROP2 might be involved in regulating the EMT and malignant progression in GBC. It also provided the first evidence that TROP2 expression in GBC was an independent prognostic factor of patients, which might be a potential diagnostic and therapeutic target of GBC.