Unlike acute diverticulitis, giant diverticulum larger than 4 cm is a rare entity with few cases described in the literature. We present a case of a 66-year-old male patient diagnosed with colonic diverticulosis. He presented to the emergency department with symptoms of acute abdomen and was diagnosed by CT scan with a 13x14 cm giant diverticulum showing signs of complication. Given the findings, an urgent surgical intervention was decided, and diverticulectomy at the diverticular neck was performed using an endostapler. The etiology of giant diverticula is related to a mechanism of one-way valve at the diverticular neck. Diagnosis poses a challenge as the clinical presentation is nonspecific. The imaging modality of choice is CT scan, which reveals a large cystic image dependent on the sigmoid colon. Definitive treatment is surgical, either by resecting the affected segment including the lesion or by performing a simple diverticulectomy in uncomplicated cases.