We report the case of a female patient who presented with signs and symptoms of tricuspid stenosis. Echocardiography revealed a sessile mass on the tricuspid valve. A diagnosis of primary cardiac tumor was made but histopathologic examination revealed the mass to be an organized thrombus. Subsequent serological tests showed elevated titers of anticardiolipin antibodies in the absence of any associated disease. This case highlights an unusual presentation of the primary antiphospholipid syndrome.