Introduction: A neuroendocrine neoplasm (NEN) is a type of heterogenous tumour originating and spreading from neuroendocrine cells and peptidergic neural crest Kulchitsky cells (silver-addicted cells). The occurrence of gallbladder NEN (GB-NEN) is extremely rare and accounting for only 0.5% of all neuroendocrine tumours and 2.1% of all gallbladder tumours. Case Presentation: A 60-year-old female with chronic cholecystitis and cholelithiasis, presented with septic shock and clinical condition suspicious of perforated viscus. The CT examination and laparotomy findings were suggestive of gallbladder carcinoma. The diagnosis of GB-NEN was later confirmed by histopathological examination and immunohistochemical studies. Following laparotomy, the patient’s condition deteriorated and succumbed to death. Discussion: The diagnosis of GB-NEN is challenging due to ambiguous clinical manifestation and existing limitations of diagnostic techniques. Immunohistochemical staining is effective in diagnosing GB-NEN and highly specific markers have been identified. Surgery remains the mainstay of treatment for GB-NEN and following adjuvant therapy may prolong survival. Conclusion Current literature on GB-NEN is scarce and the standard treatment plan is under exploration. Early detection of GB-NEN improves prognosis and is encouraged for patients with chronic cholecystitis and cholelithiasis. Individualised treatment plan should be emphasised to maximise patients’ benefits in clinical practice.