Primary cardiac synovial sarcoma is an uncommon malignant neoplasm, with only a handful of cases reported in the English literature to date. Synovial sarcomas have also been described at other unusual sites, such as the heart, pleuropulmonary region, kidney, prostate, liver, mediastinum, retroperitoneum, gastrointestinal tract, and peripheral nerve. For synovial sarcomas that arise at these unusual locations, definitive diagnosis is challenging and requires use of ancillary diagnostic procedures, such as immunohistochemistry, electron microscopy, and molecular genetic techniques, for confirmation of diagnosis. The nonrandom occurrence of t(X;18) has been found consistently in synovial sarcomas. It has also been found as a sole cytogenetic abnormality in some cases, suggesting it as a key molecular event in tumor development. This review highlights salient features of primary cardiac synovial sarcoma and the associated diagnostic challenges.