BACKGROUND Meigs syndrome is a rare neoplastic disease characterized by the triad of benign solid ovarian tumor, ascites, and pleural effusion. In postmenopausal women with pleural effusions, ascites, elevated CA-125 level, and pelvic masses, the probability of disseminated disease is high. Nevertheless, the final diagnosis is based on its histopathologic features following surgical removal of a mass lesion. Here we describe a case of Meigs syndrome with pleural effusion as the initial manifestation. CASE SUMMARY A 52-year-old woman presented with a 2-mo history of dry cough and oppression in the chest and was admitted to our hospital due to recurrent pleural effusion and gradual worsening of dyspnea that had occurred over the previous month. Two months before admission, the patient underwent repeated chest drainage and empirical anti-tuberculosis treatment. However, the pleural fluid accumulation persisted, and the patient began to experience dyspnea on exertion leading to admission. A computed tomography scan of the chest, abdominal ultrasound, and magnetic resonance imaging confirmed the presence of right-sided pleural effusion and ascites with a right ovarian mass. Serum tumor markers showed raised CA-125. With a suspicion of a malignant tumor, the patient underwent laparoscopic excision of the ovarian mass and the final pathology was consistent with an ovarian fibrothecoma. On the seventh day postoperation, the patient had resolution of the right-sided pleural effusion. CONCLUSION Despite the relatively high risk of malignancy when an ovarian mass associated with hydrothorax is found in a patient with elevated serum levels of CA-125, clinicians should be aware about rare benign syndromes, like Meigs, for which surgery remains the preferred treatment.