Introduction: Myxoma accounts for about 40-50% of all primary cardiac tumors. However, the most common site for cardiac myxoma is the left atrium. In this case report, a patient with large right atrial myxoma was diagnosed, which is an unusual site for this tumor type. Case presentation: A 42-year-old woman presented with a history of abdominal ascites in last five months and progressive dyspnea for two weeks duration. A cardiac evaluation showed sinus tachycardia and faint systolic murmur over the left lower sternal area. An echocardiogram revealed a large mass in the right atrium, suggestive of myxoma; our patient underwent surgical excision of a multilobulated mass. Moreover, a histopathological study was done, and the diagnosis was a myxoma. Conclusion: In this case study we are focusing on the importance of atrial myxoma diagnosis in an uncommon location in patients presented with dyspnea and chronic ascites.