Background: Linc00261 is a lncRNA that plays key roles in tumor suppression. While gallbladder carcinoma (GBC) is one of the most common cancer of the bile duct. However, the study about Linc00261's correlation with the clinicopathological characteristics and postoperative outcomes of the GBC patients is few. Therefore, we want to explore Linc00261 in GBC and assess its potential of clinical diagnosis. Methods: Quantitative real-time PCR (qRT-PCR) was used to detect the expression of Linc00261 in specimens of GBC and adjacent tissues as well as cell lines. Chi-square test has been used to research the correlation of the Linc00261 expression in GBC with the clinicopathological features. The Cox model was used to assess the value of Linc00261 in predicting the prognosis of GBC patients. ROC curve analysis was used to test the specificity and sensitivity of diagnostic method of serum Linc00261 expression. Results: The expression level of Linc00261 in GBC was significantly lower than normal tissues' and it was also up-regulated after surgery. The Linc00261 expression was significantly correlated with large tumor size (P4.0001), late TNM stage (P=0.008), negative liver metastasis (P=0.027) and well differentiated phenotype (P=0.017). The patients with lower Linc00261 expression had significantly worse outcomes in terms of overall survival (P=0.0188) and progression-free survival (P=0.0029), and the low expression of Linc00261 was identified as an independent risk factor affecting postoperative survival rate of the patients (P<0.01). The expression of Linc00261 in serum was down-regulated of GBC patients and increased in the patients after operation. Linc00261 expressed in serum was also positively associated with its expression in GBC tissue of patients (P<.0001). The GBC diagnosis efficacy of using the serum Linc00261 level to identify the GBC has high specificity and sensitivity (AUC 0.805). Conclusions: Linc00261 could be identified a novel gene associated with GBC development and progression. It also may serve as a new diagnostic and prognostic biomarker for patients with GBC.