We report a case of a 54-year-old man presenting with a right atrial mass 7 months after undergoing a left atrial myxoma excision surgery. The differential diagnosis included recurrent myxoma or thrombus. The patient underwent repeat open sternotomy on cardiopulmonary bypass. Histopathological evaluation of the mass revealed an organizing thrombus. This report is, to our knowledge, the first that demonstrates right atrial thrombus shortly following excision of left atrial myxoma.