Metastases are generally an expression of widespread disease and therefore warrant systemic treatment. However, clinical observations have revealed that local surgical treatment might be beneficial in the case of organ-confined metastatic disease. Randomised studies have revealed that in the case of brain metastases, metastasectomy followed by radiotherapy, has a favourable outcome with respect to both the quality of life and overall survival. Retrospective non-randomised studies in selected patient groups show prolonged post-treatment survival in the case of both lung and liver metastasectomy. The most important prognostic factors for metastasectomy are: disease control elsewhere in the body, tumour species, the patient's general condition, and the possibility of a total resection of the metastasis. These factors form the basis of the separate decision-making process for each individual patient.