Giant mucinous cystadenomas of the ovary are seldom documented in literature within developed countries, primarily due to the widespread availability of diagnostic technologies. However, in developing nations, such situations pose a challenge owing to limited access to diagnostic tools and constrained resources. Herein, we present the case of 35-year-old women, who reported a three-year history of a progressively enlarging giant mucinous cystadenoma which was initially mistaken for obesity, accompanied by abdominal distension and pain, and was not diagnosed during the cesarean section performed three weeks prior to the significant increase in size. Cystectomy performed, the resected cyst measured 25x23x17 cm, with no evidence of ascites. Subsequent histopathological analysis confirmed the diagnosis of mucinous cystadenoma. The patient experienced a complete postoperative recovery without any complications. Notably, the presence of vague gastrointestinal symptoms unrelated to the actual diagnosis underscores the importance of considering giant ovarian cysts as a potential differential diagnosis for ambiguous abdominal symptoms, given the varied clinical presentations they may manifest. This case underscores the necessity for multidisciplinary collaboration among various specialists to facilitate early diagnosis. Furthermore, it emphasizes the indispensable role of histopathological examination in ensuring accurate diagnosis and appropriate management of ovarian cysts.