We report a case of right-sided leiomyosarcoma of the kidney with concomitant poorly differentiated squamous cell carcinoma of the cervix diagnosed one month after radical nephrectomy in a previously healthy female patient. This is the first reported case of concomitant leiomyosarcoma of the kidney and squamous cell carcinoma of the cervix, and the diagnosis, clinical presentation, prognosis, and treatment are discussed.