In March 2010, a randomized trial called Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) was launched and is open to recruitment. The evidence for pulmonary metastasectomy reviewed in this supplement includes no randomized trials. Claims for a survival benefit for patients undergoing this surgery rely on case series. Furthermore, there is little documentation of any symptoms attributable to pulmonary metastases that are alleviated or obviated by metastasectomy. The PulMiCC study aims are to examine whether or not surgical resection of pulmonary metastases from colorectal cancer lengthens survival and to record systematically the harms and benefits of such surgery and quality of life.