Objective: To describe the clinical and pathological features of 49 tumors metastatic to kidney. Methods: Nonrenal solid metastatic tumors to kidneys were retrieved from the surgical pathology files at the authors’ institutions. The clinical, radiological and pathological data were reviewed. The hematopoietic tumors involving the kidney were excluded. Results: Forty-nine cases of metastatic renal tumors including lung carcinoma (n=20), gastrointestinal adenocarcinoma (n=6), cervix carcinoma (n=4), thyroid carcinoma (n=3), breast carcinoma (n=2), eye melanoma (n=2), testis germ cell tumor (n=2), hepatocellular carcinoma (n=1), uterine leiomyosarcoma (n=1), retroperitoneum seminoma (n=1), brain hemangiopericytoma (n=1), oral cavity carcinoma (n=1), salivary duct carcinoma (n=1), and ovary serious carcinoma (n=1). There were 3 cases remained of unidentified primary tumor sites. The preoperative radiological suspicion for metastasis was reported in 59.2% (29/49) of all the cases. A number of the metastatic lesions are unilateral. Of 26 radical or partial nephrectomies, 57.7% cases showed the microscopic renal sinus invasion. Renal vein invasion was presented in more than one-fourth of these cases. The metastatic tumors could resemble the histologic patterns of the primary tumors, immunohistochemical stains was necessary to reach the definitive diagnosis in some cases. Conclusion: Metastatic tumors to kidney accounting for 0.5% of all the renal tumors. The most common primary tumors are lung squamous cell carcinoma and adenocarcinoma, and gastrointestinal tract adenocarcinoma. The unilateral and single disease is not uncommon in these metastatic lesions. The presence of renal vein thrombus cannot be used to distinguish secondary neoplasm of kidney from primary ones. A histological evaluation, along with the clinical history of the malignancy involving the other organs and the radiological image, is important in reaching the correct diagnosis of renal metastatic tumors.