Background and Aims Primary neuroendocrine carcinoma of the gallbladder (GB-NEC) is extremely rare and its prognosis is generally poor. There are few studies systematically summarizing its clinical characteristics now due to the scarce cases of GB-NEC. Therefore, this study was performed to summarize and analyze the GB-NEC cases treated in the Xinghua People's Hospital, Yangzhou University and the reported cases of GB-NEC in literature in recent 20 years in order to increase the awareness of this disease.Methods The clinical data of 3 patients with GB-NEC treated in the authors' hospital were reviewed, and the relevant data of 121 reported cases of GB-NEC in literature from January 2000 to December 2020 were extracted. The general clinical feature, prognostic factors and treatment outcomes of patients were analyzed.Results The 3 GB-NEC patients were all hospitalized for non-specific symptoms including abdominal pain and underwent surgical treatment. Their specimens were confirmed as GB-NEC (including one case of accidental gallbladder cancer) by postoperative pathological and immunohistochemical examinations. All the 3 patients received postoperative adjuvant chemotherapy, and 2 cases died and one case was still alive during a short- or medium-term period of follow-up. Of the total 124 patients with GB-NEC, the median age was 58 years, female cases accounted for 62.9% (78/124), 72.1% (44/61) were small cell carcinoma and 32.5% (29/84) were mixed neuroendocrine carcinoma. The median survival time was 11 months in the whole group of patients, and was decreased as the clinical stage advanced in different clinical stage groups. Analysis of the variables of 49 patients with complete data showed that age >80 years (HR=1.364, 95% CI=1.026-1.860, P=0.049), TNM stage (stage II vs. stage I: HR=10.408, 95% CI=2.554-42.404, P=0.001; stage III vs. stage I: HR=13.167, 95% CI=3.288-52.732, P<0.001; stage IV vs. stage I: HR=38.022, 95% CI=9.738-148.459, P<0.001), surgery (non-radical surgery vs. non-surgery: HR=0.122, 95% CI=0.022-0.786, P=0.027; radical surgery vs. non-surgery: HR=0.088, 95% CI=0.019-0.481, P=0.006) and receiving chemotherapy or not (HR=0.517, 95% CI=0.305-0.983, P=0.042) were independent factors affecting survival outcomes. The increase of carbohydrate antigen 125 (CA125) level was associated with higher clinical stage (r=0.727, P<0.05). In subgroup analysis, the surgical procedure (cholecystectomy vs. radical surgery: HR=2.889, 95% CI=0.908-9.168, P=0.072) and receiving chemotherapy or not (HR=3.120, 95% CI=0.768-12.676, P=0.112) exerted no significant influence on the outcomes in stage I and II patients. The surgical procedure (cholecystectomy plus metastasis resection vs. radical surgery: HR=0.675, 95% CI=0.113-4.023, P=0.667) and receiving chemotherapy or not (HR=2.109, 95% CI=0.808-5.994, P=0.127) had no significant effect on the outcome in stage III patients. Chemotherapy offered a survival advantage in stage IV patients (HR=2.785, 95% CI=1.376-5.636, P=0.004), which was mainly reflected in patients with small cell carcinoma (median survival time: 9 months vs. 3 months, P<0.001), while was not significant in patients with large cell carcinoma (median survival time: 5 months vs. 2 months, P=0.247); Surgery did not improve the prognosis of stage IV patients (radical surgery vs. non-surgery: HR=0.533, 95% CI=0.232-1.233, P=0.138; non-radical surgery vs. non-surgery: HR=0.932, 95% CI=0.434-2.000, P=0.856).Conclusion Improving the early diagnosis efficiency is important for the prognosis of patients with GB-NEC. For staged IIII patients, surgical resection can be performed, but radical cholecystectomy is unnecessary; chemotherapy can help improve the survival rate and increase the chance of surgical resection in patients with advanced small cell carcinoma. CA125 may be used as a prognostic indicator for GB-NEC, but it still needs more studies to be proven.