A dutch national evidence-based guideline on the diagnosis and treatment of patients with colorectal liver metastases has been developed. The most important recommendations are as follows. For synchronous liver metastases, spiral computed tomography (CT) or magnetic resonance imaging (MRI) should be used as imaging. For evaluation of lung metastases, imaging can be limited to chest radiography. For detection of metachronous liver metastases, ultrasonography could be performed as initial modality if the entire liver is adequately visualised. In doubtful cases or potential candidates for surgery, CT or MRI should be performed as additional imaging. For evaluation of extrahepatic disease, abdominal and chest CT could be performed. Fluorodeoxyglucose positron emission tomography could be valuable in patients selected for surgery based on CT (liver/abdomen/chest), for identifying additional extrahepatic disease. Surgical resection is the treatment of choice with a five-year survival of 30 to 40%. Variation in selection criteria for surgery is caused by inconclusive data in the literature concerning surgical margins.