BACKGROUND: The ability of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) to impact on management of patients with recurrent colorectal cancer is high. However, direct impact of FDG-PET on surgical management of patients with potentially resectable hepatic metastases is limited. METHODS: FDG-PET scans of patients with colorectal cancer at Austin Hospital in a 2-year period were retrospectively evaluated. Data were collected on patient demographics, scan indication and sites of disease pre- and post-PET. Results of standard imaging tests and FDG-PET scans were analysed. The potential impact of FDG-PET on proposed surgical management plans was assessed by an experienced surgeon. RESULTS: There were 585 FDG-PET scans performed on 470 patients (309M : 161F, mean age 61.9 years) with colorectal cancer. Hepatic metastases were identified on standard imaging in 232 (39.7%) patients, and FDG-PET confirmed hepatic metastasis in 203 cases, including 22 cases with new lesions, and clarified presence of disease in 34/37 (92%) cases with equivocal standard imaging. In 54 patients, FDG-PET was performed for disease assessment before hepatic resection. FDG-PET had substantial management plan impact in 36/54 (66.7%) patients. CONCLUSIONS: FDG-PET can profoundly impact on the management plan of patients with colorectal cancer who may be suitable for hepatic metastectomy.