Renal metastases are uncommon in clinical practice, even as autopsy reports much frequent cases în disseminated tumors. Usually multiple and bilateral, they can determine many problems of differential diagnosis in case of solitary renal mass, when a primary kidney neoplasm must be excluded. Main sources are represented by the tumors of the lung, breast, digestive tract, melanomas and lymphomas, but rare cases with other etiology have been reported. Imaging can help to the diagnosis; CT scan, MRI, transabdominal ultrasound and sometimes contrast enhanced ultrasound can be useful. The treatment is individualized by the general status, by other organs involved and by the control of primary tumors; nephrectomy can be made in cases with unsure diagnosis and if primary tumor is controlled.