Primary renal synovial sarcoma (PRSS) is an extremely rare malignancy. The diagnosis of PRSS is unforeseen due to the absence of clinical and radiological typical aspects. Here, we present a case of a 69-year-old male with complaints of hematuria and left lumbar pain. Abdominal-pelvic computed tomography scan with contrast injection showed a solid mass of 8cm diameter in the left kidney and renal vein tumor thrombus. The patient was further subjected to robotic-assisted left radical nephrectomy and renal vein thrombectomy. We concomitantly performed left adrenalectomy and paraaortic lymphadenectomy. Immunohistochemical and genetic analysis revealed PRSS. This entity is characterized by abnormal chromosomal translocation t(X;18)(p11.2; q11.2) and consequently the characteristic SYT-SSX fusion gene. Due to the disease's rarity and severity, diagnosis and management of PRSS rely upon a demanding and multidisciplinary approach.