OBJECTIVE To assess the incidence, characteristics and prognostic significance of calcification within colorectal hepatic metastases. METHODS A retrospective analysis of CT in 265 patients with locally advanced or metastatic cancer was performed. Four groups were defined: (a) calcification within liver metastases prior to therapy, (b) noncalcified liver metastases with development of calcification on therapy, (c) noncalcified liver metastases, and (d) advanced local tumour without liver metastases. The number of calcified deposits in each patient was documented. A marker lesion was analysed for character, distribution and percentage of calcification. Survival between the four groups was compared. RESULTS Twenty-nine (11%) patients had calcified liver metastases at presentation and 10 (4%) developed calcification during chemotherapy. Analysis of a marker lesion showed that the most frequent characteristic was fine calcification with a variable distribution. The most frequent change on treatment was alteration in the extent of calcification. Calcification developing on treatment was usually central. There was no difference in survival between groups 1, 2 and 3, but groups 1, 2 and 3 had a shorter survival than group 4. CONCLUSIONS Calcification of liver metastases shows a variable pattern and may develop or change during therapy. Liver metastatic calcification may not carry any prognostic significance in colorectal cancer.